The Atlantic Forest has been threatened by frequent human disturbances that affect its ecological processes. Lianas are an important component of tropical forest dynamics and, under chronic disturbance, may proliferate vigorously, potentially arresting secondary succession and hindering forest recovery. Our study aims to analyze abundance and diversity of liana and trees in different life stages in a disturbed semidecidual seasonal tropical forest fragment in southeast Brazil. We sampled the species richness and relative abundance in the following life stages of lianas and trees: I—seed (as seed arrival and seed bank processes), II—seedling, III—juvenile, and IV—adult. Lianas are more abundant than trees after the seedling stage, while trees showed more rarefied species richness only at the seed rain stage. Our results show that dispersal does not seem to be a bottleneck for either liana or tree community in disturbed fragments, but competition at the seedling stage may give lianas advantage over trees. Lianas may proliferate abundantly in forest fragments, even decades after disturbance. We recommend interventions for the management and restoration of disturbed forest fragments dominated by lianas to target this life form in life stages where they suppress the forest community, such as after the seedling stage.