It is understood that mate choice, competition, and sex differences produced by sexual selection underlie behavior, but few studies focus on their interactions within a system to understand how they shape behavior. Here, using the monogamous convict cichlid, Archocentrus nigrofasciatus, we examined the mate choice process of males and females in the presence of intrasexual competition. We compared and contrasted patterns reported in a previous study exploring this process in the absence of competition by using the same methodological paradigm. Specifically, two individuals (i.e., the competitors) were presented with a choice of two alternative, visually and tactilely isolated, mates and observed until one competitor (i.e., the primary competitor) spawned with one of the potential mates (i.e., the accepted mate). This was done for males and females separately. Both sexes spent more time with their mates while attacking and inhibiting the courtship of the other competitor (i.e., the secondary competitor). Only females expressed this time preference in the absence of competition (Santangelo & Itzkowtiz, 2004), but both sexes visited accepted mates more in the presence of competition. These results suggest competition causes the adoption of a mate guarding tactic. Males exhibited more differences than females with the addition of competition suggesting that male mate choice patterns are more labile than females. We attribute this to the ability of males to be bigamous and the adoption of different strategies based on the level of male-male competition. Courtship was not affected by competition for either sex, however the courtship of secondary individuals did appear to be influenced by primary individuals. Competition did not eliminate a searcher's continuous assessment of potential mates, yet it was conducted to a lesser degree. Thus, mate guarding is an important strategy that must be balanced with an individual's inclination to continuously assess based on present competition levels.