Thalidomide represents a recent and innovative therapeutic approach in multiple myeloma. Main toxicity usually consists in somnolence, constipation, peripheral neuropathy and deep vein thrombosis, but, unlike alkylating agents, thalidomide is reported to rarely induce severe hematologic toxicity. The majority of patients developing neutropenia are heavily pretreated with three or more lines of chemotherapy. Here, we report, for the first time, clinical and laboratory data of a 66-year-old female patient with multiple myeloma at diagnosis who, after 4 weeks of thalidomide treatment, developed a grade 4 WHO neutropenia with septicemia. A brief review of the literature and suggestions for possible predictive factors of this toxicity are made.