The lack of Omega 3 contained food intake is one of the known factors that causes poor nutritional status as well as hinders cognitive development. Fish contains high Omega 3. Cognitive development is related to movements that is affected by such skilled neural activities as learning and thinking skills while absorbing the study materials delivered by the schools (Nurjanah, 2008). This research aims to  nd out the relationship of Omega 3 intake to cognitive development in students of SD Saptosari, Gunungkidul.This study is an observational study, completed with Cross Sectional design, that is conducted in SD Saptosari, Gunungkidul, Yogyakarta. The data was gathered in the period of March to September, 2016. The respondents of the study were elementary school students. The bivariant testing used in the study involved Liniear Regression testing.The average consumption of Omega 3 was 74.09 ± 7.81 and the average cognitive development was measured through the marks the students got, that was 75.01 ± 7.88. The correlation testing showed an average relationship (r = 0/274) between the two variables. The liniear regression testing showed a signi cant relationship (p = 0/006), with 0.075 determining coef cient. The regression formula was Cognitive Development = 54/563 + 0.276 Omega 3, meaning that the cognitive development reaches 0.276 with every 1 mg Omega 3 consumption. The conclusion isthere is a relationship between Omega 3 consumption and cognitive development in students of SD Saptosari, Gunungkidul, Yogyakarta. It is suggested to improve the potential of the cognitive skills of SD Saptosari students through  sh consumption as the source of Omega 3.