BACKGROUND: Cerebral white matter lesions (WMLs) and lacunar infarcts (LIs) are mostly caused by small vessel disease (SVD). Whereas the main pathomechanism behind LIs is SVD, a variety of mechanisms could be responsible for WMLs. We tried to investigate the relationship between WMLs and LIs and the impact of subtypes of WMLs on its relationship. METHODS: We assessed 128 subjects with vascular cognitive impairment with subcortical vascular lesion (VCI-S). LI number and WML volume were determined on T1-, T2-weighted images and fluid-attenuated inversion recovery images using a semiquantitative visual scale. Cognitive function and daily functional impairment were assessed with Mini-Mental State Examination (MMSE) and the Seoul-Instrumental Activities of Daily Living (S-IADL). RESULTS: Of the 128 patients, 106 (82.8%) had Alzheimer's disease with WML and 22 (17.2%) had subcortical vascular dementia. Seventy patients (54.7%) had at least one lacune. A univariate Poisson model showed that history of hypertension, history of stroke and WML volume (periventricular and deep subcortical) were associated with LIs. A multivariate Poisson model showed that increased WML volume of both types and history of hypertension were associated with LIs. Neither S-IADL score nor MMSE was significantly associated with WML volume of both types. CONCLUSIONS: We found that LIs were associated with WMLs regardless of their types in patients with VCI-S. These findings may suggest that periventricular and deep subcortical WMLs share the same vascular pathomechanism of SVD as LIs.