Polylactic acid (PLA) microneedles have emerged as a highly promising tool in dermatology, offering minimally invasive treatment options for a broad spectrum of skin conditions. These innovative microneedles present numerous advantages, including enhanced patient comfort, precise drug delivery, and superior cosmetic outcomes. This chapter provides a comprehensive review of the development, mechanisms, and diverse applications of PLA microneedles in dermatology, emphasizing their pivotal role in drug delivery, cosmetic treatments, and therapeutic interventions. Moreover, the chapter elaborates on the benefits of PLA microneedles, such as biodegradability and customization, while also addressing challenges like mechanical strength and manufacturing complexity. Future prospects in this domain are explored, with a focus on ongoing research and potential advancements that could further extend the clinical applications of PLA microneedles, thereby improving patient outcomes and advancing the field of dermatological care.