Download the People Group List (16 languages .csv)

Amharic - አማርኛ | Arabic - عربي
Bengali - বাংলা | Chinese (Simplified) - 中文（简体）
Chinese (Traditional) - 中文（繁體) | French - Français
German - Deutsch | Gujarati - ગુજરાતી
Hindi - हिन्दी | Indonesian - Bahasa Indonesia
Korean - 한국어 | Nepali - नेपाली
Portugese - Português | Russian - Русский
Spanish - Espanol | Tagalong / Filipino
Be sure to use the data import function in your favorite app for working with data.
If you'd like to help improve these translations, Contact Us.

PEOPLE GROUP PROFILE

The Big Sepik of Papua New Guinea

The Big Sepik of Papua New Guinea, numbering approximately 18,500 people, are No Longer Unreached. They are an indigenous ethnic group of Papua New Guinea and can also be known as Latmul, Nyaura. They are an Indigenous people, in the New Guinea people cluster of the Pacific Islanders affinity bloc. Their primary religion is Christianity - Roman Catholicism. They primarily speak Iatmul.

Photo by Google. (2025). Image generated by Gemini 2.5 Flash: Big Sepik

Fast Facts:

Affinity Group: Asian Pacific Rim Peoples
Country: Papua New Guinea
People Cluster: New Guinea
Primary Language(s): Iatmul (ian)
Primary Religion(s): Christianity - Roman Catholicism
Population: 18,500
Strategic Progress Index (SPI): No Longer Unreached
Global Status of Evangelical Christianity (GSEC): 5% or Greater but Less than 10% Evangelical
People Group ID: PG009782

Prayer Card
Submit Updates

Pray for the Big Sepik of Papua New Guinea

Join others around the world in praying for the lost to be saved, the gospel to advance, the global Church to grow, and for laborers to be sent out and sustained in the harvest.

Pray Now!
Download Prayer Guide

Dig Deeper (Religion):

Primary Religion: Christianity - Roman Catholicism
Religious Affiliation: Christianity

%
Christianity - Roman Cath… Adherents

Dig Deeper (Language):

Primary Language: Iatmul
Language Family: Ndu

%
Iatmul Speakers

Media Resources in Iatmul:

Films:

No entries found for: Iatmul(ian). Help build some!

Provided by the Jesus Film Project

View all resources

Bible Resources in Iatmul:

Provided by Faith Comes by Hearing

Or check out the Iatmul bible resources at Bible.com

Linked from YouVersion

View all resources

Next steps for the Big Sepik

The Big Sepik are Unengaged and Unreached, which means there are less than 2% evangelical Christian populations among which there are no known efforts focused on establishing self-sustaining churches consistent with evangelical faith and practice.

Begin signifcant prayer and fasting for this group
Send cross-cultural teams to discover and research this people group
Begin gospel seed sowing and church planting among this group

Next steps for the Big Sepik

The Big Sepik are Engaged yet Unreached, which means there are less than 2% evangelical Christian populations but there are sustained efforts at establishing self-sustaining churches consistent with evangelical faith and practice.

Continue prayer and fasting for this group
Continue gospel seed sowing and church planting among this group
Begin training up local leaders to lead and develop strategies to reach their own people

Next steps for the Big Sepik

The Big Sepik are No Longer Unreached, which means there are more than 2% evangelical Christian populations and there are churches consistent with evangelical faith and practice. There is still more to be done among them.

Empower local believers to begin praying for their own people
Continue gospel seed sowing and church planting among this group
Encourage local leaders to being leading church planting strategy and looking for Unreached and Unengaged groups nearby

Pray specifically for the Big Sepik of Papua New Guinea

Hear, O LORD, and be merciful to me! O LORD, be my helper!
readPsalm 30:10

Pray that people in the depths of despair and suffering and living outside of relationship with Christ will cry out to the Lord and find help, peace, and joy in Him.

For what can be known about God is plain to them, because God has shown it to them. For his invisible attributes, namely, his eternal power and divine nature, have been clearly perceived, ever since the creation of the world, in the things that have been made. So they are without excuse.
readRomans 1:19-20

Pray that God will use His creation – the “things that have been made” – to spark a fresh and passionate curiosity among them to draw near to the Maker and that, as they seek Him, He will make a way for them to hear the gospel and receive it with joy.

So neither he who plants nor he who waters is anything, but only God who gives the growth.
read1 Corinthians 3:7

Pray that as people place their faith in Christ, they will be unified in making disciples and be used by God to further His kingdom near and far.

How beautiful upon the mountains are the feet of him who brings good news, who publishes peace, who brings good news of happiness, who publishes salvation, who says to Zion, "Your God reigns”
readIsaiah 52:7

Pray that God will provide open doors for believers who cross cultures to share the good news of salvation with those who need it. Pray that He will give them joy as they see Him move.

Big Sepik (ROP3 - 101423) reported in the following countries:

To download a comprehensive people group list in spreadsheet form, visit our Research Data page.

Peoplegroups.org relies on updates from the field and other organizations for much of our data, so if you have any updates, please contact us. We use various international naming standards. For a list of these standards and fields, visit our Definitions page.

Scroll to Top