Inclusion Criteria:

• Pathologic diagnosis of Non-Hodgkin's Lymphoma of the mantle cell sub-type lymphoma only, as determined by morphologic assessment and consistent immunophemotypic markers
• Newly diagnosed and patients who have received prior treatment are eligible
• Measurable or evaluable disease
• Karnofsky performance status greater or equal to 50%
• Men and women, age greater or equal to 18 years old
• AGC greater or equal to 1.0; platelets greater or equal to 75,000; Hemoglobin greater or equal to 8.0 (unless because of lymphomatous infiltration of the marrow)
• Creatinine less than 2.0; bilirubin less than 2.0; SGOT less than 3 times upper limit of normal (unless elevations are due to lymphomatous involvement)
• Women of child bearing potential must have negative pregnancy test within 14 days of study entry.
• Signed informed consent

Exclusion Criteria:

• History of congestive heart failure or significant cardiac disease
• Prior exposure to either fludarabine or mitoxantrone. Prior exposure to rituximab allowed
• Active infection
• HIV seropositive
• Pregnant or lactating females
• Second active malignancy, other than squamous cell skin cancer,in-situ cervical cancer, or history of other cancer diagnosed within the preceding 5 years
• Presence of psychological or emotional disorders which would make valid informed consent impossible