Despite being an important source of protein, fish consumption in Peru is low compared with other coastal countries. Thus, the objective of this study is to identify the core determinants of such consumption. We based our analysis on the framework provided by the Theory of Planned Behavior (TPB) where attitudes, subjective norms, past experience and health involvement determine the intention and frequency of fish consumption. Primary data were gathered through 159 consumers of fish in modern Metropolitan Lima between August and October 2015. From a set of likert scale indicators a structural model was specified to evaluate the relationships given by the theoretical framework of the TPB. The results showed that the intention to eat fish is determined by personal attitudes, norms and past experience, and as expected, intention itself causes the frequency of fish consumption. Nonetheless, although consumers’ interest in healthy eating was shown to positively influence fish consumption behavior by theory, Metropolitan Lima fish consumers seem to be not concerned by positive health attributes related to fish consumption. These results may have important implications on production decisions, sales and marketing for the promotion of fish in Lima as a means of economic development.