Background An inflammatory condition leading to stiffness and pain in the shoulder joint, adhesive capsulitis is associated with conditions such as diabetes mellitus, cervical spondylosis, thyroid dysfunction, autoimmune rheumatic diseases, and shoulder injury due to trauma, fracture, rotator cuff tear, surgery, or immobilization. Adhesive capsulitis may affect a notable proportion of the diabetic population. There are numerous studies that show that patients with type 2 diabetes mellitus are not only at higher risk of developing adhesive capsulitis but also suffer poor outcomes despite treatment, especially in patients with long-standing diabetes mellitus. Furthermore, there is significant variation in data regarding the prevalence of adhesive capsulitis in Pakistani patients with type 2 diabetes mellitus. Objective To determine the prevalence of adhesive capsulitis among patients with type 2 diabetes mellitus presenting to a tertiary care hospital in Bahawalpur, Pakistan. Methods The present observational cross-sectional study was carried out at the Department of Medicine, Bahawal Victoria Hospital, Quaid-e-Azam Medical College, Bahawalpur, Pakistan, from February 2024 to August 2024. Type 2 diabetes mellitus was labeled by HbA1c of more than 7.0%, or two random blood glucose levels of 200 mg/dL or more, or an existing diagnosis of diabetes mellitus, and/or use of anti-hyperglycemic therapy. Adhesive capsulitis was diagnosed clinically on the basis of history (gradual onset shoulder pain with limitation of movements) and examination (reduction in active and passive range of motion (ROM) of the shoulder, especially abduction, internal rotation, and external rotation) in the absence of significant abnormalities on shoulder X-ray. After ethical approval and obtaining informed consent, 430 patients with type 2 diabetes mellitus were included in the study using a non-probability consecutive sampling technique. Demographic information, diabetes control, and HbA1c levels were noted, and the patients were assessed for adhesive capsulitis. All the data was recorded and entered into IBM SPSS Statistics for Windows, Version 23 (Released 2015; IBM Corp., Armonk, NY, USA), for analysis. Results Having a female preponderance (266, or 61.9%), the mean age of the participants was 54.0 ± 13.1 years. With regard to occupational status, 126 (29.3%) had a sedentary occupation, 45 (10.5%) were unemployed, and 259 (60.2%) had a non-sedentary occupation. The mean diabetes duration was 6.4 ± 5.3 years, and the majority of patients had poor diabetes control (322, or 74.9%). Adhesive capsulitis was present in 61 (14.2%) patients with type 2 diabetes mellitus. On stratification, no significant statistical association of adhesive capsulitis was seen with gender (p-value: 0.075), age (p-value: 0.465), occupation (p-value: 0.056), diabetes duration (p-value: 0.118), or diabetes control (p-value: 0.090). Conclusion Adhesive capsulitis was not an uncommon finding in our study, reported in almost one-fifth of the 430 patients enrolled. We recommend that treating physicians screen diabetic patients for adhesive capsulitis so that proper pain relief, physiotherapy, and rehabilitation may be provided timely and efficiently, thereby reducing morbidity and improving the quality of life for such patients.