 For marginal zone lymphoma MZL Rituximab in combination with conventional chemotherapy are widely used for those patients who fail local therapy or do not qualify for such. Depending on the MZL subtype Rituximabchemotherapy is able to induce in part long remissions, but do not prevent relapse later on. In addition, chemotherapy associated toxicity is often problematic in MZL patients, who are mostly of advanced age. Thus, chemotherapy - free approaches are highly attractive for this patient group. Rituximab single agent is a widely used chemotherapy - free approach in MZL, but was significantly inferior compared to Rituximabchlorambucil in a large randomized prospective clinical trial in treatment naïve MZL with a CR rate of 56 vs. 80, respectively P0.001.Thus, it is the major aim to develop chemotherapy - free approaches for MZL, which approach efficacy of rituximabchemotherapy combinations, but avoid chemotherapy associated toxicities. This in particular important in MZL as many physicians are reluctant to treat these often elderly patients with more intense treatments and prefer single agent therapies in these very often well and long responding lymphoma subtype. The type II anti-CD20 antibody Obinutuzumab OBINUTUZUMAB has demonstrated remarkable activity in follicular lymphoma and superiority to Rituximab in combination with chemotherapy in treatment naïve Gallium trial and rituximab refractory follicular lymphoma Gadolin trial as well as in CLL in combination with chlorambucil. Based on these observations it is the aim of this study to test the toxicity and efficacy of the anti-CD20 antibody Obinutuzumab OBINUTUZUMAB in patients with newly diagnosed MZL in need of treatment, who are not eligible or failed local therapy, following the assumption that this novel anti-CD20 antibody is significantly more effective than Rituximab single agent therapy, and avoids chemotherapy - related toxicity. 