In foot biomechanics, the medial longitudinal plantar arch plays a critical role. It is the most essential reference in determining the degree of flat foot since it serves as a footing and shock absorber while walking. It operates as an adaptable support basis for the entire body, dissipates weight-bearing forces, and stores energy throughout the gait cycle. Although arch complex dysfunction is typically asymptomatic, it can affect the biomechanics of the lower limbs and lumbar spine, increasing the risk of discomfort and injury. Consistent measurements can be used to ascertain foot types (such as flat feet and normal feet) based on their arches, as these describe the foot’s plantar surface contact area. Staheli's Plantar Arch Index (SPAI) is used to analyze these arches where a ratio between the widths of the mid foot and the heel region of the foot is gotten; this is called the Plantar Arch Index (PAI). A descriptive cross-sectional design was used to recruit 427 Rivers State indigenes of the university. The students were clustered into 15 tribes in Rivers State and 29 students were randomly selected from each of the tribes. Foot impressions were retrieved via the ink and paper method. The plantar arch index was used to diagnose and analyze for flat foot. 211 males and 216 females were recruited for the study with a mean age of 24 years ±3. The prevalence of flat feet among the respondents was 12.6% where males accounted for 42.6% and females accounted for 57.4%. Females were recorded to have a higher prevalence. It was also observed that among the respondents, there was an 11.1% and 88.9% prevalence of unilateral and bilateral flat feet respectively. This study among Rivers State indigenes in Rivers State University disclosed a prevalence rate that is comparable to other adult population. Females exhibited a greater risk of this disorder, so should be given special attention. It is recommended that proactive efforts be made in the areas of screening, prevention