The effects of static stretch on muscle and tendon mechanical properties and muscle activation were studied in fifteen healthy human volunteers. Peak active and passive moment data were recorded during plantarflexion trials on an isokinetic dynamometer. EMG monitoring of the triceps surae muscles, real-time motion analysis of the lower leg and ultrasound imaging of the Achilles-medial gastrocnemius muscle-tendon junction were simultaneously conducted. Subjects performed three 60-s static stretches before being re-tested 2 min and 30 min post-stretch. There were three main findings in the present study. First, peak concentric moment was significantly reduced after stretch; 60% of the deficit recovered 30 min post-stretch. This was accompanied by, and correlated with (r = 0.81; P<0.01) reductions in peak triceps surae EMG amplitude, which was fully recovered at 30 min post-stretch. Second, Achilles tendon length was significantly shorter during the concentric contraction after stretch and at 30 min post-stretch; however no change in tendon stiffness was detected. Third, passive joint moment was significantly reduced after stretch, and was accompanied by significant reductions in medial gastrocnemius passive muscle stiffness; both measures fully recovered by 30 min post-stretch. These data indicate that the stretching protocol used in this study induced losses in concentric moment that were accompanied by, and related to, reductions in neuromuscular activity, but were not associated with alterations in tendon stiffness or shorter muscle operating length. Reductions in passive moment were associated with reductions in muscle stiffness, whereas tendon mechanics were unaffected by the stretch. Importantly, the impact on mechanical properties and neuromuscular activity was minimal at 30 min post-stretch.