Generalized pustular psoriasis of pregnancy (GPPP) is a rare and severe condition that may impair the health of the mother and fetus. Effective treatment is essential, as treatment options for GPPP are limited due to concerns about unfavorable pregnancy outcomes. We report the case of a 22-year-old woman with GPPP that was unresponsive to systemic corticosteroids. We effectively treated the condition with infliximab at 30 weeks' gestation with an immediate clinical response and no detected serious adverse events except for an oral herpes infection in the patient and low birth weight in the neonate. Future studies are necessary to evaluate the safety and efficacy of infliximab treatment in GPPP.