The overarm throw is a fundamental motor skill that requires integral coordination of the upper and lower extremities in order to produce a successful throwing action. Research confirms the gender differences in the overarm throw starts as early as preschool and progresses with magnitude with age. This study examined gender differences in developmental trajectories of the overarm throw in preschoolers that resulted from overarm throwing instruction. The participants, 117 preschool children (66 boys and 51 girls) (M = 53.60 + 9.2 mos) received 80 minutes of direct throwing instruction as part of an 8-week fundamental motors skills intervention. Overarm throwing instruction centered on target throwing with the incorporation of cue words and environmental task modifications. Data analysis used Roberton and Halverson's (1984) throwing components (step, trunk, backswing, humerus, and forearm) that progress from primitive to advanced attractor states of the overarm throw. Prior to data analysis, inter-rater reliability between three raters was established on each overarm throwing component. Pre-intervention data revealed that the majority of boys and girls demonstrated primitive overarm throwing profiles (S1T1B1H1F1). This represents no step, no trunk rotation, no backswing, humerus oblique, and no forearm lag. The post-intervention data revealed that a majority of boys and girls demonstrated a short contralateral step and blocked trunk rotation. Boys exhibited more advanced throwing components in the backswing, humerus, and forearm compared to the girls. The intervention resulted in boys exhibiting a circular upward backswing, an independently aligned humerus, and forearm lag while the girls displayed an elbow-humeral flexion backswing, humerus oblique, and no forearm lag. A 4 x 2 x 4 or 3 x 2 x 3 log linear analysis design (Kennedy, 1992) was used to test for statistical differences by gender in each overarm throwing component. Consistent with the literature boys outperformed girls in the overarm throw, and only boys were able to reach the highest profile reported, S4T3B3H3F3 (e.g. long contralateral step, differentiated rotation, circular upward backswing, humerus lag, and delayed forearm lag). It is imperative that physical educators continue to explore instructional interventions that will lead to greater attainment in the acquisition of fundamental motor skills in girls.Keyword(s): early childhood, gender issues, performance