The purpose of this study was to explore the efficacy of 150 mg once monthly oral risedronate use in the prevention of sleeve gastrectomy (SG) associated bone loss. Twenty-four SG patients (56 ± 7 years, 83% female, 21% black) were randomized to risedronate or placebo for 6 months, with an optional 12-month assessment. Outcome measures included 6 (n = 21) and 12 (n = 14) month change in dual energy x-ray absorptiometry-acquired regional areal bone mineral density (aBMD). Six-month treatment effect estimates [mean (95% CI)] revealed significant between group aBMD differences at the femoral neck [risedronate: +0.013 g/cm2 (−0.021, 0.046) vs. placebo: −0.041 g/cm2 (−0.067, −0.015)] and lumbar spine [risedronate: +0.028 g/cm2 (−0.006, 0.063) vs. placebo: −0.029 g/cm2 (−0.054, −0.004)]; both p ≤ 0.02. When followed postoperatively to 12 months, differential aBMD treatment effects were observed at the total hip [risedronate: −0.035 g/cm2 (−0.061, −0.009) vs. placebo: −0.072 g/cm2 (−0.091, −0.052)] and lumbar spine [risedronate: +0.012 g/cm2 (−0.038, 0.063) vs. placebo: −0.052 g/cm2 (−0.087, −0.017)]; both p < 0.05. Preliminary treatment effect estimates signal 6 months of risedronate use may be efficacious in reducing aBMD loss at the axial skeleton post-SG, with benefit largely maintained throughout the 1-year postoperative period. Confirmatory data from an adequately powered trial are needed.