Microplastics, plastic particles between 0.0001 and 5 mm in diameter, are ubiquitous in the environment and are known to be consumed by organisms, leading to a variety of adverse effects. Our current study focused on identifying the effects of microplastic consumption on the growth, foraging and competitive interactions of juvenile convict cichlids (Archocentrus nigrofasciatus) and its effects on their behavioural decision making. We manipulated the levels of microplastic consumption among cichlids by feeding them brine shrimp (Artemia spp.) exposed to different concentrations of virgin polyethylene microspheres. Cichlids were exposed to microplastics for 10 days, during which we analyzed their foraging behaviour and competitive aggression during days 1, 6 and 10 of the experiment. Additionally, we measured their growth by mass. Following the 10-day exposure, we measured exploratory behaviour in a simple maze trial by quantifying latency to exploration, maze completion and shoaling. We performed the maze trial across two days and assessed differences in these metrics to make inferences on their learning ability. Initially, we found no impacts of microplastic exposure on foraging rate, growth, and competitive aggression. In contrast, we found significant effects on exploratory behaviour and maze performance. Fish exposed to microplastics exhibited higher latency to exploration, lower rates of maze completion and a larger change in their behaviour on the second day. Our current results show that virgin polyethylene microplastics at non-lethal levels have consequences on cichlid behaviour and cognition but not growth.