This study aimed to examine cardiorespiratory responses to six basic aquatic exercises and to compare the impact of the exercises between healthy females (H group, n =10) and females with diagnosed cardiopulmonary diseases (C group, n =10). The average age of the participants was 52.6(±5.9) years. Each exercise was performed for 3  min. During the exercises, heart rate (HR), oxygen consumption (VO 2 ), blood lactate concentration (BLA), and rate of perceived exertion (RPE) were measured. In each pair of exercises, the latter part was more strenuous than the first. Walking in place was least and cross-country skiing the most strenuous mode of exercise. Energy expenditure (EE) ranged between 2.5±0.8 MET in the C group and 6.0±1.6 MET in the H group. RPE ranged between 11.0±2.5 in the C group and 13.6±2.4 in the H group. The C group had significantly lower HR in cross-country skiing and running forward, as well as lower VO 2 in running in place, cross-country skiing and running forward, as compared to the H group. BLA in the C group was significantly lower than in the H group. We conclude that the studied aquatic exercises may be utilized as an aerobic exercise with moderate to moderately high strain for both groups. [ABSTRACT FROM AUTHOR]