Severe flank pain is a frequent complaint at the emergency department (ED). It is usually associated to other clinical symptoms like fever, dysuria, vomiting, diarrhea or radiation to the groin. Hereby, it may raise a lot of probable differential diagnosis that should be ruled out first depending on laboratory tests and imaging results. However, when flank pain is isolated and radiating to the groin without evidence of urolithiasis on abdominal CT scan, more rare diagnosis should be suggested such as renal vessels thrombosis with or without other vessel thrombosis in the pelvis. Thereafter, thrombophilic studies should be performed to elucidate the underlying etiology. We present the case of a 44-yearold lady having simultaneously acute left renal and ovarian veins thrombosis presenting to ED for severe isolated left flank pain radiating to the left groin and heterozygous factor V Leiden on thrombophilic studies. We would like to stress on the importance of having a high index of suspicion of such diagnosis at ED based on medical history and primary investigations because a good management may result in salvage of organs by minimally invasive techniques, an early effective treatment and convenient anticoagulation in the future to prevent further complications.