Objective: Among hypertensive individuals, prevalence of sleep apnoea-hypopnea syndrome ranges from 30% to 40%, while 50% of patients with SA are hypertensive. Classically, SA has been associated with a "non-dipping blood pressure profile", usually defined as a nocturnal fall in blood pressure of less than 10%, regardless of the presence of hypertension in the daytime. Aim was to investigate the dipping patern in the observed group of patients with sleep apnoea-hypopnea syndrome. Design and method: Research included 100 patients who underwent polysomnograpic examination in UCC Kragujevac. According to apnea-hypopnea index (AHI) all patients were divided into 3 equal groups, 25 patients in each group (AHI 5-15; 15-30 and >30). Fourth group was a control group with 25 patients without sleep apnea. All patients were evaluated for prior hypertension and antihypertensive therapy. Diagnosis of hypertension was confirmed, and blood pressure profile, including dipping pattern, were assessed using ABPM technique and classified according to the latest guidelines. All data were statistically analyzed in the SPSS for Windows. Results: Study population consisted of 69% of male and 31% of female patients with mean age of 55.05 +/- 11.16 years. Prior hypertension was present in 76% of patients (x2 = 27.04; p = 0.000) in total group, and 62% (x2 = 7.31; p = 0.007) among patients with diagnosed sleep apnea-hypopnea. Non-dipping of systolic blood pressure duing 24 h recording was present in 37% of study population (x2 = 16.40; p = 0.007) and for diastolic blood pressure in 31% of patients in total group. When observed according to the severity of SA, SBP non-dipping pattern was the most pronounced in patients with AHI >30, with 15% of patients having nocturnal fall less than 10% (x2 = 14.84; p = 0.095). Diastolic BP non-dipping pattern was nearly equal in all patients. Conclusions: Non-dipping blood pressure profile was present in observed patients with sleep apnoea-hypopnea syndrome, with higher prevalence of systolic than diastolic non-dipping profile. Systolic non-dipping profile is present especially in patients with severe sleep apnoea-hypopnea syndrome. Copyright