Lentigines are defined as multiple small pigmented macules measuring up to one centimeter and surrounded by normal-appearing skin, commonly caused by genetic factors. LEOPARD syndrome (LS) is an autosomal dominant distinguished by the presence of several lentigines, with specific phenotypic characteristics that resembles Noonan syndrome (NS). LS is likely to be underdiagnosed or misdiagnosed because many of its symptoms are minor and the accurate diagnosis may be overlooked. Therapy for lentigines are generally aimed at tackling aesthetic disfigurement and its subsequent psychological impacts. This case report aims to highlight the efficacy of 532-nanometer (nm) Q-switched (QS) Nd:YAG laser in treating lentigines in a 21-year-old woman with LS overlap NS. The patient initially came to seek treatment of her facial lentigines. However, some mild abnormalities such as ocular hypertelorism, left eye ptosis, and webbed neck were observed. Hormonal, cardiac, and pulmonary functions were within normal limit. Histopathological results supported the diagnosis of lentigo. The patient was given sunscreen and depigmenting agents and was instructed to apply the medications routinely. The patient then underwent two sessions of 532-nm QS Nd:YAG laser with a 3 mm spot size, 1 J/cm2 fluence, and a 1 Hz frequency. Objective clinical improvements were observed using spectrophotometer examination, there were no side effects found, and she was satisfied with the results. Dermatologists should play an integral role in establishing the diagnosis and management of systemic syndrome, manifesting specifically as dermatological symptoms. Lentigines in LS last throughout the patient's lifespan. Nd:YAG laser therapy can be effective in treating lentigines with long-lasting results. It plays a role in improving the patient's life quality, especially where the genetic disorder itself is a debilitating condition. The limitation of this case report was the lack of a genetic test, as the suspected diagnosis was made based on clinical symptoms.