In an effort to effectively conserve and exploit the germplasm resources of Sterculia monosperma Vent., a comprehensive assessment and diversity analysis was conducted on 70 germplasms of this species. This study employed a robust set of statistical methodologies including diversity, cluster, correlation, principal component, and stepwise regression analyses. Variability in thirteen fruit traits was examined, with the coefficient of variation ranging between 7.80% and 42.94%. Notable variability was observed particularly in traits such as single fruit weight, single fruit seed weight, starch content, soluble sugar content, and soluble protein content. The genetic diversity index across these traits spanned from 1.57 to 2.04, with the seed-form index, starch content, seed longitudinal diameter, and fruit seed number displaying higher diversity indices, indicative of a substantial genetic variation. Through cluster analysis, the germplasms were segregated into four groups, with Group II consisting of 15 resources identified as larger fruit-bearing and aesthetically superior, aligning with market preferences and breeding objectives. Principal component analysis elucidated that the primary four components accounted for 74.46% of the total variance in the 13 assessed fruit traits. Furthermore, a comprehensive evaluation yielded a score range (F) from -2.95 to 3.35 for the fruit traits, with germplasms S009, S021, S011, S036, and S028 demonstrating superior comprehensive attributes. Finally, stepwise regression analysis delineated four pivotal trait indicators—single fruit seed weight, seed weight, soluble sugar content, and seed transverse diameter—as essential for the holistic assessment of the Sterculia monosperma Vent. fruit traits. These indicators are proposed to guide future conservation strategies and breeding programs for this species.