Thirty-four volunteer obese housewives, who have not done exercise regularly during the last six months and have had no health problems to prevent them from exercising, have participated in the study. For the participating volunteers (n = 34), their age averages have been determined as (39.30 ± 11.30 years), their average height have been determined as (166.40 ± 8.50 cm) and their average body weights have been determined as (82.44 ± 15.02 kg), their average BMIs have been determined as (26.03 ± 6.65 kg/m[superscript 2]) and their average body fat percentages have been determined as (32.17 ± 8.05 %). The volunteers have been given an aerobic exercise program at 75% an exercise intensity according to the Karvonen formula for 50 minutes a day and for 4 days a week during 12 weeks. Measurements (body weight, waist circumference, body fat percentage) of the volunteers have been taken at the beginning and the end of the 12-week aerobic program. The data have been analysed by using the SPSS 17.0 statistical package program. Statistical analyses have been made by using Wilcoxon Test and the significance value has been determined as p< 0.05. After the statistical analysis, statistically significant difference have been detected between the preliminary and the final test values of the subjects in terms of Body Weight (z = -5.08, p<0.05), Waist Circumference (z = -5.08, p<0.05), Body Fat Percentage (z = -4.71, p<0.05) and Body Mass Index (z = -4.57, p<0.05). As a result, it has been determined that aerobic exercise of 12 weeks in aerobic style has positive effects on physical fitness parameters of obese housewives. For this reason, the importance of the cost-free aerobic exercise in the right intensity for every age has been revealed again.