Granular parakeratosis is an uncommon acquired keratinization disorder that occurs in the armpit, groin, and other parts of the body. It may be related to stimulation by detergents and antiperspirants. This article reports a case of granular parakeratosis in the groin. The patient was a young man with no predisposing factors. The clinical manifestations included symmetrical bilateral inguinal erythema, dryness, and a small amount of bran-like desquamation. After histopathological examination, the final diagnosis was granular parakeratosis, which was cured by topical application of glucocorticoid cream and silicone oil cream. Granular parakeratosis is a rare skin disease of unknown etiology. Clinicians need to pay attention to this disease and differentiate it from various diseases to avoid misdiagnosis.