Snow crabs, Chionoecetes opilio, were obtained approximately bimonthly from the eastern Bering Sea and sampled for biometric information and biochemical analysis of ovaries, which included determination of moisture, ash, total lipid, protein content, fatty acid and lipid profiles. Development of the ovary during the reproductive cycle largely followed the pattern seen in other crustaceans, namely an increase in size and lipid content. However, the increase in lipid content occurred early in the development cycle and was stable thereafter. Both the lipid and fatty acid profiles were relatively stable throughout development. The fatty acid profile of the ovary of C. opilio differs from other crustaceans by having relatively high percentages of eicosapentaenoic (EPA) and docosahexaenoic acid (DHA), and low percentage of arachidonic acid (ARA). Forward stepwise general discriminant analysis of fatty acid profile indicated that it can be used to classify the development of ovaries at least during the last five months of the yearly reproductive cycle.