The purpose of this study was to examine the thermal effects of both 1.0W/cm2 and 1.5W/cm2 at 3MHz with continuous US while the triceps-surae is immersed in 37°C water. Intramuscular tissue temperature increases observed through the thermocouples at 1.5W/cm2 was compared to 1.0W/cm2. The study is needed to determine which intensity was most efficient at increasing intramuscular tissue temperature in the triceps-surae at a 1.5cm depth. Twenty college students, 10-males and 10-females (M=23.45 ± 1.986-years), participated in 2 sessions. A thermocouple measuring intramuscular temperature was inserted into the gastrocnemius muscle. There were no significant differences in intramuscular temperature increases at 0-minutes (M=0.1320, SE=0.5617), 5-minutes (M=-0.3570, SE=0.5617), and 10-minutes (M= -0.6885, SE=0.569). This study indicated no significant difference between intensities 1.0W/cm2 and 1.5W/cm2 throughout a 10-minute treatment. Clinically selecting appropriate parameters should be done to best treat patients. This study provides evidence that increasing intensity does not always increase tissue temperature.