The dynamics of forest regeneration in a tropical rainforest ecosystem in South-western Nigeria as exemplified by International Institute of Tropical Agriculture Forest Reserve, Ibadan, Nigeria was assessed. Twenty-four sample plots of 25 × 25 m each were used to assess all plants ≥ 5 cm diameter at breast height (dbh) (1.3 m) in each plot for density, height, dbh and frequency. Detrended Correspondence Analysis (DCA), similarity and diversity statistics were used to analyze the data. A total of 1,328 trees (885.33 trees/ha) from 57 species and 28 families were encountered. Dominant families include Moraceae, Sterculiaceae, Papilionaceae, and Sapindaceae. Lecaniodiscus cupanioides, had the highest density (94.67 trees/ha) with Relative Importance Value (RIV) of 20.81% while Euadenia trifoliolata, Malacantha alnifolia, Solanum enriathum and Zanthoxylum zanthoxyloides, had the least RIV of 0.640, 1.24, 0.79 and 0.64%, respectively. Species such as Lecaniodiscus cupanioides, Newbouldia laevis, Spondia mombim, Sterculia tracagantha, Antiaris toxicaria, Milicia excesla, Funtumia elastica and Albizia zygia were identified as universal species. Simpsons’ diversity indices ranged from 0.375 to 0.924 for all the plots. The equitability index ranged from 0.793 to 0.985 for all the plots, while the basal area ranged from 0.052 to 27.809 m2/plot. The cumulative stem diameter class of 10 to 44 cm accounted for 72.57% of the total number of stems in the forest estate. High Eigen value (73.3%), length of ordination space coverage (-3 to 6) and the location of all the plots in the first quadrant indicated that the environment was stable; indicating minimal variation in floristic composition between plots and high heterogeneity of the site and species respectively. Conclusively, this study demonstrated that natural regeneration could be an effective strategy for restoration of tropical tree species, diversity, canopy height, tree stem density and size distributions. Key words: Ordination, density, species, diameter-class, relative importance value.