Abstract Background Ceratitis capitata Wiedemann (Diptera: Tephritidae) (Mediterranean fruit fly), is one of the important polyphagous pest species in the world that harms almost all fruits causing significant yields losses. Control of this pest which is on the quarantine list of many countries is highly important. Due to the negative effects of chemical control on the environment and human health, biological control approaches have gained importance. Entomopathogenic nematodes (EPNs) are a potential biological control agent that can be used for effectively controlling the Medfly. Results In this study, effects of four EPNs species on larvae, pupae and adults of Medfly were investigated under laboratory conditions. Four different concentrations of EPNs species were used against each stage of the pest. It pest showed different sensitivity to different concentrations of each of the tested EPNs. High mortality rate of 94% was caused by Heterorhabditis bacteriophora (11 KG),, followed by H. bacteriophora (TOK-20) with 91%, Steinernema carpocapsae (85%) and S. feltiae (Tokat-Emir) with 71% at highest concentration (200 IJ/larvae. The highest effect on adult mortality (100%) was recorded by the species S. feltiae (Tokat-Emir) at the highest concentration (200 IJ/adult) in the trials, followed by H. bacteriophora (11 KG) with 92%, H. bacteriophora (TOK-20) with 91% and S. carpocapsae (Tokat-Bakışlı05) with 87.37% mortality rates at the same concentrations. Conclusions It was determined that the EPNs tested in this study had insecticidal properties and they might be used in biological control programs against the Medfly.