Resistant schizoaffective disorder has persistent psychotic symptoms and intermittent mood swings. A satisfying method for treating these patients is the use of the antipsychotic drug clozapine, but its use is limited due to significant side effects such as leukopenia and neutropenia. Lithium carbonate is another psychiatric drug that reduces these side effects. We hypothesized that lithium, along with clozapine, in addition to controlling side effects, could have a dual effect on mood episodes in schizoaffective disorder, and used it in a chronic case. The patient was a 48-year-old man with a 20-year history of the disease. Therefore, the use of lithium along with clozapine is recommended in refractory schizoaffective patients.