Skeletal-related events (SREs) are common in patients with osteolytic lesions from multiple myeloma (MM), and result in substantial morbidity. We report herein a comprehensive, retrospective, multivariate analysis of prognostic factors for survival and first on-study SRE in MM patients using data from the phase III, randomized study comparing zoledronic acid with pamidronate in MM or breast cancer. Cox regression analyses were used to assess 22 variables for prognostic significance (defined as associations with P<0.05) in patients with bone metabolism marker assessments and complete baseline variable data. Of 510 evaluable MM patients, 282 had complete covariate information and were included in models. Reduced Cox multivariate models identified five significant prognostic factors for first SRE (weight, race, high N-terminal cross-linked telopeptide of type I collagen (NTX), high pain score, and need for narcotic analgesics) and seven for survival (age, SRE history, myeloma subtype, anemia, high lactate dehydrogenase, high NTX, and low albumin levels). High NTX was the only variable associated with elevated risks of both first SRE and death (P< or =0.02 for each). These analyses identified prognostic factors for SREs and survival in patients with MM. Taken together with current staging systems, these factors could further facilitate decision making for optimal treatment of myeloma bone disease, although further prospective assessments are needed.