Anogenital warts (AGWs) are globally recognized as the most common sexually transmitted infections (STIs) caused by the human papillomavirus (HPV), particularly types 6 and 11. Meanwhile, immunotherapy is one of the treatments of choice for patients with extensive AGWs. Measles, mumps, and rubella (MMR) vaccine induce the production of various T helper 1 cytokines to elicit immune responses, resulting in the clearance of both treated and untreated warts. This study reported a case of extensive genital and extragenital warts in a 53-year-old male which had occurred for five years, with no pseudo-Koebner phenomenon. The history of MMR vaccination was uncertain but the patient received oral antibiotics for one week, one month before seeking consultation. Physical examination showed extensive verrucous and hyperkeratotic papules, plaques, and nodules in the lower abdomen, pubic, inguinal, genital, and gluteal regions. Acetowhite test results were positive, while polymerase chain reaction (PCR) results were positive for HPV types 6 and 11. The patient received an intralesional injection of 0.5 mL MMR vaccine into the largest warts with a 3-week interval. However, during the one-month follow-up after the third injection, no improvement was observed in either the size or number of warts. Based on the results, several factors must be considered to determine the best candidate for immunotherapy, particularly with MMR vaccine, to achieve an optimal outcome. These factors include the active state of diseases, duration of diseases, as well as a history of sensitization, and broad-spectrum antibiotics.