Abstract The present research attempted to extend prior research that showed that thin-slices of pre-performance nonverbal behavior (NVB) of professional darts players gives valid information to observers about subsequent performance tendencies. Specifically, we investigated what kind of nonverbal cues were associated with success and informed thin-slice ratings. Participants (N = 61) were first asked to estimate the performance of a random sample of videos showing the preparatory NVB of professional darts players (N = 47) either performing well (470 clips) or poorly (470 clips). Preparatory NVB was assessed via preparation times and Active Appearance Modeling using Noldus FaceReader. Results showed that observers could distinguish between good and poor performance based on thin-slices of preparatory NVB (p = 0.001, d = 0.87). Further analyses showed that facial expressions prior to poor performance showed more arousal (p = 0.011, ƞ 2 p = 0.10), sadness (p = 0.040, ƞ 2 p = 0.04), and anxiety (p = 0.009, ƞ 2 p = 0.09) and preparation times were shorter (p = 0.001, ƞ 2 p = 0.36) prior to poor performance than good performance. Lens model analyses showed preparation times (p = 0.001, rho = 0.18), neutral (p = 0.001, rho = 0.13), sad (rho = 0.12), and facial expressions of arousal (p = 0.001, rho = 0.11) to be correlated with observers’ performance ratings. Hence, preparation times and facial cues associated with a player’s level of arousal, neutrality, and sadness seem to be valid nonverbal cues that observers utilize to infer information about subsequent perceptual-motor performance.