Enhancement of the sterile male performance in Bactrocera philippinensis through access to protein (yeast hydrolysate) and/or exposure to methyl eugenol (ME) was investigated in this study. The temporal occurrence of sexual maturity of B. philippinensis was determined for both laboratory sterile and wild flies. Laboratory tests were also conducted to determine the peak age of ME feeding in relation to male fly age and sexual maturity and effect of protein on the longevity of sterile males. Field cage mating tests were performed to examine the effect of adult diet (P+ vs. P−) and ME exposure (ME+ vs. ME−) on the mating competitiveness of the sterile male B. philippinensis. P+ME+ sterile male flies achieved significantly more matings with wild females than P+ME− or PE−ME− sterile males. Based on the relative sterile index, P+ sterile male flies were significantly more sexually competitive when competing for wild females than P− flies. The results confirm that the pre-release diet can be significantly improved to increase the effectiveness of the application of the sterile technique against B. philippinensis.