Spontaneous Ovarian Hyper Stimulation Syndrome (OHSS) is an extremely rare and intriguing entity. In an era of increasing demand for assisted reproductive techniques, drug induced OHSS has become a commonly anticipated and encountered event. Spontaneous OHSS on the other hand requires high index of suspicion, or else misdiagnosis and unnecessary surgical intervention would complicate the scenario. This is a case of spontaneous OHSS in a primigravida at 9 weeks of planned spontaneously conceived pregnancy with primary hypothyroidism