The introduction of rituximab into the primary treatment of malignant lymphomas of the B cell lineage has had a major impact on the management of these diseases. In addition, prolonged exposure to rituximab as maintenance therapy has been beneficial in patients with follicular lymphoma and mantle cell lymphoma. For the individual patient, the effect of any prolonged antitumor therapy on the quality of life (QoL) is a very important question. However, so far, the question whether rituximab maintenance therapy may impair QoL in patients with non-Hodgkin's lymphoma remains unanswered. To investigate this subject, we have performed a prospective randomized trial of rituximab maintenance therapy (8 cycles rituximab 375 mg/m(2) every 3 months) versus observation in patients with CD20+B cell non-Hodgkin's lymphoma in our institution. Between July 2002 and December 2005, 122 patients were included into the trial. QoL was assessed with the standardized questionnaires EORTC-QLQ-C30, EuroQol-5D, and EuroQol-5D (VAS) in 91 patients. After statistical analysis with the exact Wilcoxon rank sum test, we found no significant differences of the QoL between the rituximab treatment group and the observation group. We conclude that rituximab maintenance therapy seems to be safe and does not impair quality of life in this patient population.