OBJECTIVES: To determine the incidence of DVT following caesarean section, to identify the significance of various risk factors for DVT and to assess correlation of clinical features in relation to objective tests for DVT. DESIGN: A Prospective Cohort Study. SETTING: Professorial Obstetric unit, De Soysa Hospital for Women (DSHW), Colombo. METHODS: Six hundred & eleven women who underwent caesarean section during a period of nine months (1st of March 2003 to 31st of November 2003) in the above unit. Data was collected by an Interviewer-based pre-tested questionnaire, from case notes, physical examination and by doing non invasive colour Duplex ultrasonography and real time ultrasound scan. The principal investigator was trained to do real time ultrasound scan and colour Duplex at the Department of Surgery in Colombo. The principal investigator collected the data from all the subjects. The …