A recent phase III trial demonstrated that maintenance rituximab® therapy after response to first-line treatment with rituximab plus chemotherapy (R-chemo) increases progression-free survival (PFS) for follicular non-Hodgkin lymphoma (f-NHL). A cost-effectiveness analysis of R-maintenance versus observation was conducted from a US payer perspective to estimate PFS and overall survival (OS) over a representative patient's lifetime. Primary outcomes were cost per life-year gained (LYG) and cost per quality-adjusted life-year (QALY) gained. Compared with observation, R-maintenance increased mean PFS by 1.50 years, OS by 1.21 years and QALYs gained by 1.11 years. The incremental cost of maintenance therapy was $38,545. The costs per LYG and QALY gained were $31,934 and $34,842, respectively. Within the limitations of modeling long-term outcomes, R-maintenance therapy in patients who received R-chemo for previously untreated f-NHL compared with observation alone after R-chemo for first-line treatment for f-NHL is cost-effective from the US payer perspective.