Background: Rural health clinics may be an effective site for the delivery of weight management in rural communities. However, rural clinic staff trained to deliver weight management may be unavailable. This secondary analysis used data from a trial which randomized rural adults (BMI = 35 kg/m2) to a weight loss intervention delivered by group phone (GP, n = 71) or individual phone (IP, n = 80) (DK108732) to examine the impact of the type of interventionist (clinical staff nurse/dietician (CS) vs. allied health professional health educator/kinesiologist (AH P)) on 6 mo. weight loss. Methods: All interventionists (CS = 4 2 registered nurses, 2 registered dietitians; AHP = 2 1 health educator, 1 kinesiologist) were trained to deliver a multicomponent weight management intervention that included education/behavioral counseling, reduced energy diet, increased physical activity and self-monitoring. Interventionist training included a detailed intervention program binder and a 1-day on-site, and four 1-h. remote sessions. A factorial model was performed to compare the effect of interventionist type (CS vs AHP), delivery mode (GP vs. IP), and their interaction on weight change (%) across 6 mos. Results: Six-mo. weight loss was significantly greater in the GP (-11.7 ± 6.6%) compared with the IP arm (-9.2 ± 6.8%; p < 0.01). There was a significant interaction between delivery mode and interventionist type. In the IP arm weight loss was significantly greater when the intervention was delivered by CS (-10.9 ± 6.5%) compared with AHP (-5.7 ± 6.0%; p = 0.02). However, in the GP arm weight loss not significantly different when the intervention was delivered by CS (-11.3 ± 5.9%) or AHP (-12.7 ± 8.1%, p > 0.05). Conclusions: Our findings suggest that interventionist type did not impact 6 mo. weight loss when the weight loss intervention was delivered in a group-based format. However, when using an individual format weight loss was significantly greater when the intervention was delivered by CS compared with AHP.