Abstract: van den Tillaar, R and Marques, MC. Reliability of seated and standing throwing velocity using differently weighted medicine balls. J Strength Cond Res 27(5): 1234–1238, 2013—The aim of this study was to test the reliability of throwing velocity in a seated chest throw action and in a standing overhead situation with 3 differently weighted medicine balls using a Doppler radar gun. To test the reliability of throwing velocity of the 2 different techniques and various weights, a repeated measurement setup was used. Seventy-nine (55 men and 23 women) college sport science students performed standing overhead throws and seated chest throws with medicine balls weighted 1, 3, and 5 kg. A systematic bias was found (p < 0.001) in overhead throwing but not in seated chest throwing. Furthermore, the variability of maximal throwing velocity decreased with increasing ball weights and was much higher in standing throws compared with that in the seated chest throws. The retest correlations (intraclass correlation coefficients) were high in all throwing tests, varying from 0.88 to 0.96. It was concluded that measuring throwing velocity using the Doppler radar gun in standing overhead throws and seated chest throws with different weights shows high reliability. However, reliability is affected by throwing weight and throwing technique, which can be of relevance when conducting studies and testing training effects with these parameters.