Focal segmental glomerulosclerosis (FSGS) is the most common histological pattern of nephrotic syndrome which has been mainly reported in adults with hematological malignancies. However, the association of FSGS with carcinoma especially solid tumor of the thyroid has not been reported. Here, we present a case of nephrotic syndrome developed due to renal failure in a 21-year old woman with autosomal dominant polycystic kidney disease (ADPKD). Pathological examination of renal biopsy revealed the characteristic changes of FSGS. On further evaluation, the patient had right thyroid lobe swelling clinically which result in total thyroidectomy. The pathological study was inconsistent with papillary thyroid carcinoma (PTC). Regardless of the therapeutic interventions, her renal function worsened gradually and she ultimately required hemodialysis. This case presented an unreported co-incidence of PTC and nephrotic syndrome due to FSGS. The underlying mechanism for the development of malignancies after nephrotic syndrome is still unknown. Hence, underlying malignancy should be considered in young adult patients presenting with nephrotic syndrome.