The goal of any real estate investor is to maximize return. This can be achieved through the generation of rental income. Thus, it is pertinent that the nature and characteristics of rental value are understood by investors to enhance real estate market penetration. This study examined commercial real estate rental variation in Ilorin, Nigeria, with specific focus on commercial complexes. For data collection, the study area was delineated into three commercial zones. Primary data for the study were collected from occupiers of commercial complexes and property valuers operating within these areas through structured questionnaire, based on purposive sampling technique. The study utilised an analysis of variance (ANOVA) technique to analyse the variation in rental values of commercial complexes in the study area. Results of data analysis revealed a statistically significant variation in rental values of commercial complexes in the study area (F ꞊ 16.70809, p ≤ 0.05) and an increasing trend of the rental values over the years under study as indicated by the rental index. This variation is perceived to be caused by the safety and quality of location, building visibility and lease term (RII ꞊ 0.97, 0.93 and 0.88, respectively). The study recommends that real estate investors should consider these factors when investing in commercial complexes across the commercial zones in Ilorin.