OBJECTIVES:   Evidence suggests that primary prophylaxis with filgrastim (Neupogen®, administered daily for 10-11 days per chemotherapy cycle) or pegfilgrastim (Neulasta®, administered once per chemotherapy cycle) is equally effective.  Patients often receive shorter (<7 days) courses of filgrastim in clinical practice.  Using filgrastim for fewer days may reduce costs, but it has been associated with an increased hospitalization risk.  Economic evaluations (EEs) may be used to guide decisions in resource allocation.  The objective of this review is to identify and characterize the EEs of primary prophylaxis with filgrastim versus pegfilgrastim in patients with solid tumor cancer receiving myelosuppressive chemotherapy. METHODS:   We performed a systematic literature search of the EMBASE, MEDLINE, Cochrane Library, Google Scholar, ABI/Inform, and the Web of Science using such search terms “filgrastim,” “pegfilgrastim,” “cost analysis,” and “economic evaluation.”  Studies were limited to primary research in patients with solid tumor cancer, specifically, studies comparing filgrastim with pegfilgrastim and resulting in full manuscripts.  Identified studies were evaluated by the Drummond checklist and characterized by study perspectives, time horizon, data sources, and funding. RESULTS:  Six studies fulfilled the inclusion criteria.  Most studies modeled hypothetical cohorts of women aged 30-80 years with breast cancer (Stages I-III) from a payer’s perspective.  The median Drummond score was 9 of 10 (range, 8-9).  Methodological and reporting variations were common.  Key assumptions were made about FN-related deaths during chemotherapy, hospitalization and outpatient management, chemotherapy costs, and data sources.  All six studies were funded by the drug manufacturer.  Pegfilgrastim was found to be cost-saving compared to 11-day filgrastim.  However, when compared to 6-day filgrastim, the choice of intervention depends on the decision-maker’s willingness-to-pay.  CONCLUSIONS:  Variations in methodology, reporting, and assumptions made comparisons between studies difficult and may explain in part the observed results reported in EEs.  Studies independent of industry sponsor are needed to make conclusive interpretations.