Hairy cell leukemia (HCL) is a rare chronic B cell leukemia morphologically characterized by cells with an abundant cytoplasm and hair-like projections that can be found in the peripheral blood and bone marrow. The treatment for HCL is splenectomy or chemotherapy with the purine analogs pentostatin and cladribine. However, patients continue to relapse. Retreatment with the same or alternate purine analogs produces lower response rates and a shorter duration of response. Fludarabine is another purine analog widely used in treating indolent lymphoid cancers, often in combination with rituximab. Here, we report a case of HCL variant in a 60-year-old man who experienced multiple relapses after splenectomy and retreatment with cladribine. The patient was then treated with fludarabine and rituximab combination chemotherapy. After the treatment, he achieved complete remission that continued for 35 months.