Polycystic ovary syndrome (PCOS) and thyroid diseases are two common disorders in the female population. These conditions seem to be correlated even if the cause is still unknown. They are characterized by overlapped clinical manifestations and risks, including reproducing, and metabolic aspects. Both diseases could cause a reduction in fertility and an increase in insulin and lipid levels. This review is focused on the connection between PCOS and hypothyroidism and their different treatments, such as inositol, oral contraceptive, insulin-sensitizers for one and levothyroxine, selenium, iodine for the other. In PCOS women a high prevalence of subclinical hypothyroidism (SCH) and autoimmune thyroid disease is found. Therefore, different treatments are examined with more attention on efficacy and safety of inositols, as a therapeutic approach for either PCOS and SCH.