Background: Softball pitching is a ballistic, complex movement that requires an underhand windmill motion to create force and ball velocity. In addition to proper pitch biomechanics, upper and lower extremity strength and joint motion likely contribute to ball location accuracy and velocity. Yet, the number of studies reporting muscle strength and joint range of motion among softball pitchers is scarce.Objective: To assess differences between throwing and nonthrowing shoulder, elbow, and hip (lead and trail leg) strength and range of motion (ROM) in high school and collegiate level softball windmill pitchers. Design: Cross-sectional study. Participants: Thirty-three female softball pitchers (24 high school, 9 collegiate) were recruited from local teams. Methods: Goniometric joint ROM and handheld dynamometer strength measurements of the bilateral shoulders, elbows, and hips were measured. Main Outcome Measurements: Goniometric joint ROM of the bilateral elbows (flexion, extension), shoulders, and hips (flexion, extension, internal rotation [IR], external rotation [ER]). Handheld dynamometer strength measurements of the bilateral shoulders (flexion, extension, abduction, IR, ER), elbows (flexion, extension), and hips (flexion, extension, IR, ER, abduction). Results: Across all pitchers, there was greater shoulder flexion ROM in the nonthrowing limb than in the throwing limb (P = .004). There was greater hip extension in the lead leg than trail leg. Among high school pitchers, there was greater shoulder ER (x = 105.792 AE 7.11) than collegiate pitchers (x = 100.1 AE 6.92), P = .05. There was no difference in total arc of shoulder rotational motion (ER+ IR) between throwing and nonthrowing limbs across all pitchers, nor between high school and collegiate pitchers. Strength measures demonstrated greater throwing limb shoulder abduction (P = .006) and IR strength (P = .001) than the nonthrowing shoulder across all pitchers. Elbow flexion strength was significantly greater than the nonthrowing side (P = .001). No difference was noted in hip strength between lead and trail lower extremities. Conclusions: Developing normative data for softball pitchers upper and lower extremity strength and range of motion may allow providers to assess players more comprehensively and identify athletes out of the expected value range. This information may help in guiding strength and conditioning programs for softball pitchers.