Social influences can impact self-presentational concerns such as social physique anxiety (SPA), concerns over one's body being evaluated by others. In addition, social influences may also impact performance on a physical test. In a physical testing environment, one social factor that influences SPA and which may also influence the outcomes of a physical test is experimenter gender. The present study examined the influence of experimenter gender on SPA and actual muscle strength in an experimental testing environment. Male (n = 50) and female (n = 50) university students were randomly assigned to either a male or female experimenter. Before strength testing, state SPA (SPA-S) was assessed. Actual strength was represented by the score obtained during the maximum voluntary contraction (MVC) test. Two 2 × 2 (participant gender × gender of the experimenter) analyses of variance were conducted with SPA-S and strength as the dependent variables. For SPA-S, a significant main effect was found only for participant gender (F(1,95) = 14.08, p < 0.01, η² = 0.13), with women scoring significantly higher than men. For MVC, there was a significant effect for participant gender (F(1,96) = 48.08, p < 0.001, η² = 0.33), with men, as expected, having significantly higher strength values than women. Although the gender of the experimenter did not influence SPA-S or muscle strength, other forms of anxiety (e.g., fitness anxiety) may be relevant in this setting. Future research should also investigate other factors in the testing environment (e.g., type of task) that may be more influential on psychological or performance outcomes.