The association between diabetes and subclinical hypothyroidism (SCH) were reported. Thus, the present study was conducted to find out the relationship between type 2 diabetes mellitus (T2DM) and SCH in Saudi patients with T2DM. A total of 1156 subjects with T2DM were included in this study. Average age of the study population was 55.1 ± 16.2 years. SCH was present in 121 (10.5%) where females were statistically significant more prevalent than males in patients with HbA1c 7-9 % (p=0.006). There was a trend up as age advanced where females were statistically significant more prevalent than males in the forth decade (p=0.02). SCH was statistically significant present in 8.7, 10.6 and 14.9% in patients with HbA1c <7, 7-9 and >9% respectively (p=0.03). Patients with HbA1c 7-9 and >9% were statistically significant older compared to patients with HbA1c<7 (p=0.02) with females were statistically significant more prevalent in patients between HbA1c <7, 7-9 and >9, (75.0, 60.6% and 62.3%) respectively, p= <0.0001. Only HbA1cwas found to be an independent predictor of SCH (P=0.03). A statistically significant negative correlation was observed between TSH and HbA1c(r= -0.007, P= 0.8). Also, a significant negative correlation was observed between FT4 and HbA1c(r= −0.053, P= 0.1). Conclusion: SCH is highly prevalent in cohort of Saudis with poorly controlled patients with T2DM.