Background: More than 80% of leg ulcers are caused by venous insufficiency. The actual causes of venous ulcers, beyond the presence of venous insufficiency, are rarely referred to in the literature. This study evaluates the direct triggers for ulceration in patients with venous insufficiency. Methods: Sixty-four patients with 110 chronic venous ulcers, treated in the Chronic Wounds Clinic of Soroka University Medical Center from 1999 through 2002, were included in the study. In each patient, the actual trigger of ulceration was determined by history taking and reviewing of the medical chart. Results: The actual triggers of ulceration, based on data for 64 patients with an overall total of 110 ulcers, were identified as follows: cellulitis (or erysipelas), 17 ulcers (15.4% of 110 ulcers); penetrating injury, 13 ulcers (11.8% ); contact dermatitis, 12 ulcers (10.9% ); rapidly aggravating leg edema, 12 ulcers (10.9% ); burn wound, seven ulcers (6.3% ); dry skin with subsequent scratching, six ulcers (5.4% ); blunt trauma, five ulcers (4.5% ); deliberately self-inflicted trauma, five ulcers (4.5% ); insect bite, two ulcers (1.8% ); bleeding from a supeficial varicose vein, two ulcers (1.8% ). In 29 ulcers (26.3% ) no specific trigger was identified. Conclusions: The development of a cutaneous ulcer is not necessarily “ spontaneous” and should not be attributed solely to the presence of venous insufficiency. In many cases, it is possible to identify a specific trigger that causes the ulceration. Clinical implementation of the above findings in routine examination and treatment of patients with venous insufficiency may prevent the development of venous ulcers. Background: More than 80% of leg ulcers are caused by venous insufficiency. The actual causes of venous ulcers, beyond the presence of venous insufficiency, are rarely referred to in the literature. This study evaluates the direct triggers for ulceration in patients with venous insufficiency . Methods: Sixty-four patients with 110 chronic venous ulcers, treated in the Chronic Wounds Clinic of Soroka University Medical Center from 1999 through 2002, were included in the study. In each patient, the actual trigger of ulceration was determined by history taking and reviewing of the medical chart. Results: The actual triggers of ulceration, based on data for 64 patients with an overall total of 110 ulcers, were identified as follows: cellulitis (or erysipelas), 17 ulcers (15.4% of 110 ulcers); penetrating injury with 13 ulcers (11.8%), contact dermatitis with 12 ulcers (10.9%), rapidly aggravating leg edema with 12 ulcers (10.9%), burn wound with seven ulcers (6.3%), dry skin with succeeding scratching five ulcers deliberately self-inflicted trauma, five ulcers (4.5%); insect bite, two ulcers (1.8%); bleeding from a supeficial varicose vein, two ulcers (4.5% Conclusions: The development of a cutaneous ulcer is not necessarily “spontaneous” and should not be attributed solely to the presence of venous insufficiency. In many cases, it is Possible to identify a specific trigger that causes the ulceration. Clinical implementation of the above findings in routine examination and treatment of patients with venous insucers may prevent the development of venous ulcers.