A substantial body of research has revealed that, in preparation for skilled actions such as in target sports, the heart rate slows down (cardiac deceleration) and the eyes make one long fixation on the visual target (quiet eye, QE). Despite these phenomena have each been linked with sport expertise (Cooke, 2013; Lebeau et al., 2016), and despite the putative association between cardiac deceleration and decreased oculomotor activity (Obrist et al.’s cardiac-somatic hypothesis, 1969), little is known about the relation between cardiac deceleration and QE in sports. We co-recorded ECG and eye tracking while 16 participants of varying golf ability (novices to experts) performed 60 4-m putts on a flat surface. Cardiac deceleration was operationalized in three ways: heart rate change (Delta HR) from baseline (-6 to -4 s) to action (0 to +1 s, 0 s = movement initiation) , deceleration duration (peak-to-trough interval), and deceleration magnitude (peak-to-trough amplitude). Peaks (deceleration beginning) and troughs (deceleration end) were identified for each trial and did not require fixed intervals. Three components of the QE were considered: before movement initiation (QEpre), after movement initiation (QEpost), and the sum of these two (QEtotal). Individual performance was scored as median radial error (i.e., the distance of the ball from the target). Pearson correlation tests indicated that only Delta HR and peak-to-trough interval were significantly correlated with radial error (respectively: r(14) = .538, p = .034; r(14) = -.636 p = .008). No significant correlation emerged between QE duration and performance. Importantly, cardiac deceleration and QE metrics did not show any significant correlation. Our findings extend prior knowledge by suggesting that the most behaviourally relevant feature of cardiac deceleration is its duration rather than its magnitude. Differently from previous studies, our findings cast doubt on the link between QE duration and target sport performance.