Background (.) Cupping therapy originated in Eastern Medicine, became renowned in complementary medicine and is utilized as a therapeutic treatment in contemporary medicine for musculoskeletal issues. As with any modality, there is a question of efficacy. Objective (.) This study investigated the effect of cupping therapy on muscle stiffness (MS), active dorsiflexion (DF) and perceived pain of the medial gastrocnemius muscle following a cupping therapy treatment. Methods (.) Single cohort design included 20 physically active, healthy participants (10 women, 10 men; age: 22.9 years +/- 3.35 years) completed an exercise protocol to induce delayed onset muscle soreness in both lower legs. Intervention (.) A 5-minute dry cupping treatment was performed on the dominant leg medial gastrocnemius and 5 minutes of rest for the non-dominant control leg. Primary Outcome Measures (.) Muscle stiffness, active dorsiflexion and perceived pain were measured at baseline, pre-treatment, post-treatment and 5 minutes posttreatment in the medial gastrocnemius muscle. A repeated measures ANOVA was used to analyze the main effect and interaction for condition and time. Results (.) Active DF was significantly different from baseline to pre-treatment, post-treatment and 5 minutes post-treatment (P <.001, P <.001, P =.01, respectively). Pre-treatment to 5 minutes post-treatment, active DF was also significantly different (P =.05). Active DF was significantly improved post- treatment and 5 minutes post-treatment. Baseline pain was significantly different from pre-treatment, post-treatment and 5 minutes posttreatment measurements (P <.001, P <.001, P <.001, respectively). Pre-treatment pain was significantly different from post-treatment and 5 minutes post-treatment pain (P =.009, P <.001, respectively). Post-treatment pain was also significantly different from 5 minutes post-treatment pain (P =.007). MS was not significant at any of the time points (P =.398) or between conditions (P =.140). Conclusion (.) A single cupping treatment significantly improved active DF and decreased pain was observed in the treatment group. No significant difference in MS was observed following the treatment.