The purpose of this study was to establish the reliability and sensitivity of a countermovement jump (CMJ) and perceptual wellness questionnaire in NCAA Division I men's basketball players. Twelve male collegiate basketball athletes completed 3 maximal CMJ's on a portable force plate and a customized perceptual wellness questionnaire prior to training on non-consecutive days. CMJ variables were derived from computer software and used in analysis. All CMJ variables expressed acceptable trial-to-trial reliability (CV < 8%) except eccentric duration (CV = 8.3%). Peak absolute and relative power, and absolute mean power and force were capable of detecting small performance changes with CV% < SWC%. Similar trends were observed for interday reliability with the exception of flight time to contraction time (FT:CT) (CV = 10.9%), jump height (CV =12.1%), concentric duration (CV = 9.1%) and total duration (CV = 13.6%). Perceptual wellness showed acceptable interday reliability (CV = 6.9%), however was unable to detect the SWC. When assessing the CMJ, selected variables can be used to monitor acute and chronic changes in performance. CMJ variables relating to the eccentric phase may respond differently to typical CMJ variables and may provide insight into the loading mechanisms of response. Perceptual wellness questionnaires also prove to be a reliable subjective fatigue monitoring tool.