148 patients diagnosed with sacroiliac joint dysfunction were randomized to either undergo minimally invasive (MIS) sacroiliac (SI) joint fusion, or to nonoperative treatment. The study was conducted in order to evaluate if minimally invasive operative management offered a significant benefit regarding clinical outcome when compared to nonoperative treatment. A greater success rate was reported in the MIS SI joint fusion group in comparison to the nonoperative management group at 6 months, as was a greater proportion of patients achieving a clinically relevant improvement in disability. Patients allocated to nonoperative management who crossed over to MIS SI joint fusion at 6 months reported similar improvements in pain and disability to those initially allocated to MIS SI joint fusion surgical treatment group. Rate of adverse events did not significantly differ between groups.