Pseudoangiomatous stromal hyperplasia (PASH) of the breast is a benign proliferative lesion of mammary stroma. It is identified as stromal cleavage surrounded by spindle-shaped stromal cells histomorphologicaly. Generally, it is determined in premenopausal women incidentally during breast biopsy. Clinically, it is rarely emerges as a palpable mass. PASH may be confused with low-grade angiosarcoma, hamartomas and phyllodes tumors in histopathological examination. Here, we report a giant left breast lesion that caused breast asymmetry and pain, and treated by total excision of the mass. The patient was a 39 years old women. Histopathologic examination of the specimen was evaluated as PASH. No additional medical treatment and clinical follow-up was recommended to patient. Within four months of the patient fallow-up, no problem occured.