Numerous horses have functional imbalances when standing and/or moving due to habitual grazing habits or from riding, which causes asymmetry in motion. This leads to increased weight bearing on one or more limbs, lameness, decreased performance, and pain. The objective of this randomized, controlled and blinded study was to assess the efficacy of using acupuncture for treating horses with lumbar or gluteal muscle pain. Thirty-one (31) horses were enrolled and randomly assigned to either Test Group (n = 16) or Control Group (n=15). The Test Group received dry needle acupuncture at 2 nontraditional acupoints: LU-1a (between LU-1 and LU-2) and GV-2a (between sacral vertebra 4 and 5); while the Control Group received sham acupuncture. The outcome measurement for each horse was improved scores (post- versus pre-treatment) based on a questionnaire of 9 clinical observations recorded by two observers blinded to subject group assignments. At study completion, there was a 5-fold mean improvement of the overall clinical assessment score in the Test Group (12.41 ±5.33) when compared to Control Group (2.57 ±3.22), which translated to a statistically significant difference (p = 3.55×^10-5). A secondary outcome evaluated acupuncture related sedation by counting calming signals during the treatment procedure. A statistically significant result (p = 0.038) documented greater sedation in the Test Group when compared to Control Group. The outcome of this study supported the hypothesis that dry needle acupuncture at GV-2a and LU-1a can be an effective treatment for horses with gluteal muscle and lumbar pain.