Background: Maternal and child under-nutrition is a pervasive and detrimental condition in Papua New Guinea (PNG). Despite the rapid economic growth during the past decade, the stunting rate for children under 5 has remained at 46 percent in PNG. Objective: The objective of the study was to analyze the association between the demographic, socioeconomic, and health-related factors with undernutrition for children less than five years old in PNG. Data and Method: The study used the 2009–2010 PNG Household Income and Expenditure Survey (HIES). The final sample included 3057 children under 5 years old. Logistic regression analyses were used to assess the odds of stunting, wasting and underweight. Odds ratios were adjusted for independent variables at household and individual levels. Statistical analyses were done with Stata (version 14). Findings: Logistic regression analysis showed household wealth was a significant predictor of stunting: children in the richest wealth quintile were 28.9% (0.711 [0.53–0.95]) less likely to be stunted than were children in the poorest wealth quintile. Other factors also associated with stunting include geographic locations, household head education and incidence of malaria. Similar results were found when wasting and underweight were dependent variables.