Overarm throwing performance and development has been studied using longitudinal and cross-sectional samples. Surprisingly, throwing performance of high school boys and girls has not been sampled. Gender differences in throwing performance have been identified throughout the lifespan with boys outperforming girls in distance, speed, accuracy, and developmental level (e.g. Nelson, Thomas, & Nelson, 1991; Roberton & Konczak, 2001; Roberton, Halverson, Langendorfer, & Williams, 1979). The purpose of this study was to examine throwing performance of high school boys and girls ball using ball velocities as well as to examine gender differences in relation to previous studies (Halverson, Roberton, & Langendorfer 1982; Runion, Roberton, & Langendorfer, 2003). Participants in this study included 28 girls (14.80, SD=7.29) and 26 boys (14.74, SD=7.83). Results from this study were compared to previous studies (Halverson et al., 1982; Runion et al., 2003) that included 42 girls and 47 boys with an average age of 13 years old. Procedures for both data sets were similar including: participants threw 10 times for force using tennis balls towards an unmarked curtain and ball velocity was measured directly. The average ball velocity of all ten throws for each participant was used. Independent t-tests were used to determine if significant differences existed in boys and girls throwing velocities between the previously collected data and the new data. Additionally, a t-test was used to determine the difference between genders in the current study. Results indicated that girls' throwing velocities did not significantly (F(1,68)=1.41, p =0.16) differ from the age 13 sample (16.60 ± 2.80 m/s) to the 14.80 (15.63 ± 2.84 m/s) years. Boys' throwing velocities did not significantly change (F(1,71)=.54, p= .59) from age 13(23.41 ± 4.08 m/s) to 14.74 years (23.97 ± 4.53 m/s). Significant gender differences existed (F(1/52) = 9.07, p<.0001) in both the old and new participant data. However, the gender difference in throwing velocity increased in the 14.8 year olds sample to 8.4 m/s from 6.8 m/s in the 13 year old sample. This study supports previous findings that gender differences in throwing performance continue to expand (Roberton & Konczak, 2001). Overall, girls and boys did not significantly improve their throwing velocities from 13 to 14.8 years of age. Keyword(s): gender issues, technique