The sterile insect technique is gaining an increasing role in the control of Mediterranean fruit fly, Ceratitis capitata (Wiedemann), populations. In the current study, we examine how post-teneral nutrition during the first 4–8 d after adult emergence affects performance and copulatory success in leks of mass-reared sterile (TSL strain) males. We found that protein and sugar fed males were significantly more likely to emit pheromone (call) in leks, and more likely to copulate, than males fed only sugar. Sterile males, who had access to water and apples after 4 d of feeding on protein and sugar, or sugar alone, were significantly more likely to copulate than their starved competitors who had access to water alone. However, after 24 h of starvation, 4-d protein-fed males suffered a higher mortality than sugar-fed males. More work is necessary to determine the optimal protein formulation that will maintain a balance between hastened mortality and increased sexual competitiveness of sterile males.