Summary. Although natural anticoagulant deficiencies are the established causes of thrombosis, their roles in bleeding are not fully studied. The objective is to correlate haemostatic factors with haemorrhagic symptoms quantified by a standardized questionnaire. Adult subjects were recruited from Bangkok and nearby provinces as part of routine health surveys/checkups. The validated MCMDM-1VWD form was used to assess their bleeding symptoms. At the same time, von Willebrand factor (VWF) activity, free protein S levels and protein C activity were measured. There were 5196 individuals. The mean age was 44.3 years (range 15–99) and 41% were male subjects. The mean bleeding score was −0.28 and 95% of subjects had scores between −2 and +2. The scores were lower in female subjects than in male subjects (−0.35 vs. −0.16, P < 0.001). Bleeding scores correlated negatively with age, VWF and protein C activities (Spearman’s ρ−0.258, −0.091 and −0.098, respectively, all P < 0.001), but did not significantly correlate with protein S levels. Using multivariate analysis, female gender, VWF below 100 IU dL−1, protein C below 100 IU dL−1 and protein S over 150 IU dL−1 significantly related to high (≥3) bleeding scores (adjusted odds ratio 1.95, 1.83, 1.56 and 2.84, P = 0.001, 0.001, 0.039 and 0.017, respectively). These findings may suggest interacting roles of VWF and natural anticoagulants in modifying bleeding symptoms.