Eosinophilic fasciitis (EF) and generalized morphea (GM) are rare and difficult-to-treat sclerosing skin diseases which may occur in association with hematologic disorders. We present a 66-year-old man with EF and associated Waldenström macroglobulinemia who received combination therapy with rituximab (375mg/m2 every other week, gradually extended to every eight weeks), prednisolone (1.25-30mg/d), and methotrexate (7.5-15mg/w). Three months after rituximab initiation, his skin condition improved steadily accompanied by a significant improvement in joint mobility with only mild and transitory flares (observation period: 59 months under treatment with rituximab). To date, there are five case reports on rituximab treatment of EF/GM with an association to hypergammaglobulinemia in three of those cases. Therapy effected significant improvement in four patients. Our case adds to the hitherto limited evidence that rituximab may be a promising therapeutic strategy for EF/GM in association with hypergammaglobulinemia.