Quality of life (QOL) plays an increasingly important role in the decision-making process and the ultimate acceptability of particular treatments for patients. We prospectively examined QOL in patients with advanced melanoma treated with surgery followed by heat-shock protein peptide complex 96 (HSPPC-96) vaccine, an active, patient-specific immunotherapy. QOL (the RAND 36-Item Health Survey; SF-36) and cancer-related intrusive thoughts (Impact of Event Scale; IES) were measured at the start of treatment, 3 weeks later on the final day of treatment, and at follow-up 1 month later in 30 patients with stage III or IV malignant melanoma. Mixed model analyses revealed no significant change over time in the SF-36 Physical or Mental Component Summary scores, or the IES scores. In comparisons with other populations, at the 1 month follow-up assessment, melanoma patients reported similar QOL to patients with metastatic renal cell carcinoma who received the same treatment, significantly worse QOL on the physical dimensions and similar QOL on the psychosocial and emotional dimensions compared with the general population, similar QOL to patients with type II diabetes, and significantly better QOL on all three dimensions than patients with congestive heart failure. There was also a significant negative association between IES scores at baseline and mental health scores at each time point ( < 0.002 for all). QOL remained stable during treatment with the HSPPC-96 vaccine. In addition, patients who reported high levels of cancer-related intrusive thoughts at the start of treatment reported worse mental health at the end of the treatment.