The purpose of this study was to determine the effects of 12 weeks of step aerobics (SA) training on the functional fitness of apparently healthy older women. Thirteen previously sedentary elderly women (mean age 63.14 years) participated in this study. Subjects performed 3 training sessions per week for 30-60 minutes per session. All measurements were assessed at baseline, after 12 weeks of training (posttest), and after 1 month of detraining. Assessments included the evaluation of body mass index (BMI), waist circumference (WC), strength of the upper (arm-curl [AC] test) and lower body (30-second chair-stand test [CS]), dynamic balance and agility (8 foot up and go [8 ft]), flexibility (chair sit-and-reach [CSR]), and cardiorespiratory fitness (6-minute walk test [6MW]). Step aerobics significantly improved all functional fitness components except for BMI. The 12 weeks of SA promoted a large effect size in the following measurements: WC (d = 1.6); CSR (d = 1.51); CS (d = 1.49); AC (d = 1.41); 8 ft (d = 1.32); and 6MW (d = 1.06) (p < 0.05). These results indicate that 12 weeks of SA had a positive effect on the functional fitness components of these older women. Furthermore, these findings were confirmed by the reverse effect observed after 1 month of detraining, except for upper body strength (AC test). In conclusion, 12 weeks of SA training can promote improvements in the functional fitness of apparently healthy older women. Therefore, SA can be considered an effective exercise modality to prevent the loss of functional fitness and its associated consequences.