A ruptured ovarian cyst is a common phenomenon, with presentation ranging from no symptoms to symptoms mimicking an acute abdomen. The most pressing issues facing clinicians encountering patients with potential cyst rupture in the acute setting are to rule out ectopic pregnancy, ensure adequate pain control, and rapidly assess the patient for hemodynamic instability to allow appropriate triage. Here we present a case of ruptured corpus-luteal cyst mimicking as ruptured ectopic pregnancy. 25 year old parous lady presented with 40 days of amenorrhoea and acute abdomen. On examination patientt was pale, had tachycardia with blood-pressure of 100/60 mmhg. P/V examination revealed left fornicial mass of 4x4 cm. UPT was negative, USG revealed a heterogeneously hypoechoic lesion in the left adnexa, with hemoperitoneum. A clinical diagnosis of ruptured ectopic pregnancy was made but emergency laparotomy revealed a left ovarian ruptured haemorrhagic cyst with active bleeding..In any reproductive age group, an acute abdomen should always arise a suspicion of ectopic pregnancy. However a ruptured corpus-luteal cyst should also be kept in mind. Diagnosis is done by ultrasound and treatment depends upon the presence or absence of hemoperitoneum suggestive of ruptured or unruptured corpus-luteal cyst respectively.