OBJECTIVE: The goal of this project is to evaluate the therapeutic effectiveness of fluoroscopically guided intra-articular sacroiliac (SI) joint injections in patients with diagnosed SI joint dysfunction. Patient reported outcomes related to pain and quality of life measures were evaluated. DESIGN: This is a retrospective observational study of patients receiving intra-articular SI joint injections under a single provider at the Cleveland Clinic from September 2013 to April 2019. Three hundred fifty-one patients received injections and were administered patient reported outcomes (PROs) including the Numeric Rating Scale, Patient Health Questionnaire, Pain Disability Questionnaire, EuroQol-5 Dimensions Questionnaire, and PROMIS-GH Physical and Mental Health at baseline and approximately 1-, 3-, 6-, 12-, and 24-month time points during follow-up appointments. The primary outcome measure was the percentage of patients receiving their first injection who achieved minimal clinically important difference (MCID) in these PROs at each follow-up time point. Secondary outcomes were the percentage of patients achieving MCID in each PRO for each injection analyzed (including patients who received repeat injections) and average change in these PROs at each time point for first and all injections. RESULTS: A total of 351 patients were included in the analysis, with varying time points of follow-up. The average patient age was 52.3 (±14.9) years with 74.9% female and 59.0% white. For first time injections, the MCID was achieved for Numeric Rating Scale in 60.6%, 42.1%, 47.5%, and 32.5% of patients at 1-, 3-, 6-, and 12-month follow-up, respectively. There was significant improvement in PROMIS-GH Physical Health at 3-month, 6-month, and 1-year follow-up. There was no significant improvement in PROMIS-GH Mental Health at any follow-up time points. CONCLUSIONS: Fluoroscopically guided intra-articular SI joint injection for SI joint dysfunction is effective in providing therapeutic pain relief exceeding MCID values in greater than 60% of patients at 1 month and greater than 40% at 3- and 6- months after injection. However, while this intervention may provide significant pain relief and improvement in function, it may not address the psychosocial aspect of chronic pain to the same extent.