The purpose was to examine the occurrence of sleep-related breathing disorders (SRBD) and variables related to SRBD in patients with acute lacunar stroke. In 68 consecutive patients with radiologically proven lacunes, respiratory polygraphy within the first 48 h of stroke onset was performed. SRBDs were classified according to mutually exclusive cutoff values of the apnea/hypopnea index (AHI) as mild (AHI ≥ 10), moderate (AHI ≥ 20), and severe (AHI ≥ 30). Variables independently associated with SRBDs were assessed by logistic regression analysis. The mean (standard deviation) AHI was 21.9 (17.4). A total of 69.1% of patients showed AHI ≥ 10, 44.1% AHI ≥ 20, and 25% AHI ≥ 30. Cheyne-Stokes respiration (CSR) was present in 20.6% of patients. Smoking (>20 cigarettes/day) or location of lacunes in the internal capsule or the pons was significantly more frequent in the AHI ≥ 10 group than in the remaining AHI groups (80.9% vs. 57.1%, P = 0.041). AHI ≥ 20 and AHI ≥ 30 occurred more frequently in smokers or in capsular or pontine lacunes than in the remaining patients (20% vs. 2.6%, P = 0.053; 29.4% vs. 3.9%, P = 0.01, respectively). In the multivariate analysis, smoking or capsular or pontine topographies were associated with AHI ≥ 10 [odds ratio (OR) = 3.17, 95% confidence interval (CI) 1.02–9.79; P = 0.045]. Lacunes in the internal capsule or the pons in smokers were associated with AHI ≥ 20 (OR = 9.25, 95% CI 1.05–81.70; P = 0.045). Smoking (OR = 19.64, 95% CI 1.68–229.85; P = 0.010) and body mass index (OR = 1.68, 95% CI 1.13–2.50; P = 0.010) were associated with AHI ≥ 30. Smoker patients with capsular or pontine acute lacunar stroke should be screened for SRDB.