Uterine rupture is a potentially fatal condition that usually follows previous caesarian section or difficult and obstructed labour. We describe ultrasonographic diagnosis in a case of spontaneous uterine rupture in a young second gravida, who presented in the 9th month of gestation with vague, diffuse abdominal pain for last 2 days. This event of rupture was atypical in that it occurred before the actual onset of labour, in an unscarred uterus, and with no known risk factors.