Forest fragmentation can reduce population size, affecting the plant species and their biological interactions. We evaluated the effects of fragmentation on Ficus adhatodifolia Schott ex Spreng population, aiming to answer two questions: (1) is population size sufficient to maintain reproductive fig trees throughout the year? (2) Is the mean seed production per syconium higher in the larger forest fragments? Fifty-six trees of F. adhatodifolia were visited in a year, in five fragments and one urban area in southern Brazil. Mature syconia were collected and the seed and wasp production between areas were compared. Considering all forest remnants, we recorded syconia production throughout the year, but no fragment exhibited crop production in all months. The pollinator wasps Tetrapus sp. were found in almost all syconium, thus, indicating that Ficus-pollinator mutualism was not lost. Nevertheless, smaller fragments were not capable of maintaining reproductive individuals throughout the year, therefore, requiring pollinator wasps from other fragments. The size of fragments did not influence seed production [LRT P value = 0.1; LR stat (χ2) = 4.64; n = 370]. Factors such as Ficus resilience and pollinating wasp migration may have contributed to the support of mutualism so far. Therefore, in highly fragmented landscapes such as the study region, the conservation of all forest remnants is essential to mutualistic interaction preservation. This procedure combined with the restoration of degraded areas determined by law are urgent and necessary for the conservation of regional biodiversity.