Summary Hypertension is associated with development of cardiovascular and kidney complications. Low awareness of hypertension leads to late presentation and development of complications. Studies have also shown that chronic kidney disease is often undiagnosed and patients present late. In view of the aforementioned, the prevalence and clinical correlates of decreased kidney function in newly diagnosed hypertensives were assessed. The study was carried out at LAUTECH Teaching Hospital, Osogbo, Nigeria. One hundred and forty three patients satisfied the inclusion criteria. Hypertension was defined by SBP > or = 140 and/or DBP > or = 90 mm Hg. Kidney function was assessed by glomerular filtration rate (GFR) using Modification of Diet in Renal Disease (MDRD) formula. Patients with GFR < 60 mL/min were defined as having decreased kidney function. Determinants of decreased kidney function were assessed. Thirty three patients (23.1%) have decreased kidney function. On univariate analysis, age, educational status, BMI, SBP and DBP were significantly associated with decreased kidney function. After logistic regression, age and BMI were significantly associated with decreased kidney function. Decreased kidney function was present in 23.1% of the study population. These patients stand a higher risk of faster progression of kidney disease and cardiovascular complications. This finding underscores the need to improve the awareness of hypertension in the population.