The current study reports Rasch analysis conducted to enhance the psychometric properties of the Kentucky Inventory of Mindfulness Skills (KIMS), the widely used 39-item multidimensional measure of four mindfulness traits including the following: Observing, Describing, Act with Awareness, and Accept Non-judgmentally. While this instrument has generally robust psychometric properties, the ability of its subscales to precisely discriminate between trait levels and the functioning of individual items, have not been rigorously investigated. We subjected the responses of 287 participants to Rasch analysis and found that the Rasch model fits KIMS subscales after minor modifications that involved rescoring one item, removing misfitting items, and combining locally dependent items into subtests. Precision of the KIMS can be improved substantially by using the proposed 34-item version of the instrument together with the ordinal-to-interval conversion tables presented here, without any need to modify the original response format. These findings can be useful for clinicians applying mindfulness-based interventions and researchers investigating neurophysiological and psychological correlates of trait mindfulness.