Aims: Thyroid disease is a pathological state associated significantly with diabetes mellitus (DM) Type 1 and Type 2. As the prevalence of diabetes mellitus is on the rise in our population, so the purposed significance of our study was to evaluate the frequency of thyroid dysfunction in diabetic patients of our local population. Study Design: Cross-sectional study. Place and Duration of Study: This study conducted among patients of diabetes (Type 1 and Type 2) from September 2020 to March 2021 while their visit in Holy family hospital, Rawalpindi, for a routine clinical check-up on an OPD basis. Methodology: A total of 96 patients with diabetes mellitus on regular medication, 20 to 60 years of age, were included. Patients with diabetic ketoacidosis, hyperlipidemia, pregnant females, and those taking medication that can affect thyroid functions (dopamine antagonists, antiepileptics, oral contraceptives, lithium, glucocorticoids) were excluded. A venous blood sample was drawn and sent to the laboratory to analyze thyroid function tests for the presence or absence of any thyroid dysfunction. Data analysis was done through SPSS.v.23. Descriptive statistics and Chi-square analysis was used, and a p-value of ≤ 0.05 was considered significant. Results: The mean age of the patients was 42.97 ± 10.29 years. The majority of the patients, 37.50%, were between 41 to 50 years of age. Out of 96 patients, 61 (63.54%) were male, and 35 (36.46%) were females with a male to female ratio of 1.7:1. The majority of patients, 69 (71.88%), had type II diabetes mellitus. The frequency of thyroid dysfunction found in diabetic patients was 30 (31.25%), with hypothyroidism in 19 (19.79%) and hyperthyroidism in 11 (11.46%) patients. Conclusion: This study deduced that there is a high frequency of thyroid dysfunction in diabetic patients. In the same vein, hypothyroidism was the common thyroid dysfunction associated with diabetes mellitus.