Journal of Social and Clinical Psychology 29(8): 903-929 Contextual factors may influence the efficacy and outcomes of psychological interventions. Two studies experimentally examined the effects of context on an expressive writing intervention by manipulating both the investigator’s legitimate authority and the location of writing. Students (Study 1; n = 76) and community volunteers (Study 2; n = 63) were randomly assigned to 1 of 4 experimental groups (high or low authority crossed with laboratory or home writing location) or to a control condition. Experimental groups wrote about stressful experiences and the control group wrote about time management, for 20 minutes on 3 consecutive days. These studies produced divergent, but complementary, results. Study 1 demonstrated a strong effect of writing location but no clear effects of legitimate authority. In contrast, Study 2 found no statistically reliable effects for location but demonstrated effects for legitimate authority and an interaction between location and authority manipulations for depressive symptoms. These findings provide experimental support for the view that context moderates the effectiveness of expressive writing. They also suggest that context effects common to nearly all interventions can influence efficacy and may uniquely depend on sample characteristics.