Aims: The objective was to determine if perinatal factors and umbilical cord characteristics showed any association with left-handedness in a set of twin subjects. Subjects: Twins born from 1977 to 1991 and registered in the ongoing East Flanders Prospective Twin Survey (EFPTS) were studied. Methods: Handedness as the outcome measure was assessed by the Strien (Preference score) questionnaire and the Bishop’s card-reaching test (Performance score). Perinatal and umbilical cord characteristics were compared in left and right-handed subjects, adjusting for twin clustering in the data. Random effects logistic modelling was used to predict the odds of being left-handed. Findings: Out of the 15 factors tested, only 2 had statistically significant relationships with left-handedness when assessed by Strien questionnaire. Left-handedness was less common in older fathers (odds ratio (OR) per year increase in age=0.95 (0.91-1.00) and in non-primiparous births (OR=0.68 (0.48-0.97)) Left-handedness was also less common in subjects with undefined and mixed umbilical cord windings (OR= 0.61 (0.37-1.00) when compared to clockwise windings), though the factor as a whole was not significant (p=0.13). Bishop’s test did not confirm these findings. Conclusion: Perinatal factors studied were not found to be significantly associated with left-handedness.