To evaluate the impact of a single flower visit of Xylocopa olivacea on the production of Phaseolus vulgaris Bigarre variety, its foraging and pollinating activities were studied at Dang in June 2018 and 2019. The experiments were carried out on 540 flowers labeled at bud stage and divided in four treatments: two differentiated according to the presence or absence of flowers protection regarding insect visits; the third protected and uncovered when flowers were opened, to allow X. olivacea visits and the fourth with the flowers protected, uncovered when they were opened, then rebagged without any visit. Results indicate that among 11 insect species recorded on flowers, X. olivacea ranked second and harvested nectar. Throughout the pollination efficiency of a single flower visit, X. olivacea provoked a significant increase of the podding rate, the mean number of seeds per pod, the percentage of normal seeds and the mean weight of a seed by 39.48 %, 18.19 %, 49.62 % and 31.53 % respectively. The conservation and installation of X. olivacea nests close to P. vulgaris fields is recommended to improve its pod production and seed quality