The fear of falling (FOF) limits the movements of the older adults, which, in turn, might impair postural mobility. An aquatic environment has a relatively low risk of falling and can improve motor abilities. The aim of this study was to investigate the effect of aquatic exercise on postural mobility of the healthy endomorph elderly somatotype. Therefore, 37 healthy endomorphic older adults with an average age of 64.38 ± 4.12 years participated in this study. Participants were randomly divided into four groups (i.e., Aquatic exercise, Dry-land exercise, Aquatic control, and Dry-land control). The Heath-Carter method was used to estimate the criterion somatotype, and the Tinetti method was used to determine postural mobility. Covariance analysis was used to examine the mean differences at a significance level of p < 0.05. The results showed that there was a significant difference between the aquatic exercise group and the two control groups (p < 0.01), and the dry-land exercise group was significantly different from the aquatic control (p < 0.05) and dry-land control groups (p < 0.01). The results indicate that the design of aquatic exercise programs, especially for endomorphic older adults with inappropriate body shape, for whom dry-land exercises are not appropriate, likely, has a positive effect on the motor control and both the balance and gait and provide appropriate postural mobility without FOF in older adults. © 2019 by the authors. Licensee MDPI, Basel, Switzerland.