OBJECTIVES: To examine hospital utilization in patients diagnosed with mantle cell lymphoma (MCL). METHODS: A retrospective cross-sectional study was conducted on the MedAssets health system data for inpatient and outpatient visits diagnosed with MCL for the January 2009 to December 2014 timeframe. Age and gender, clinical comorbidities and measures of utilization including number of visits and length of stay (LOS) were described. Multivariable regression was used to identify significant drivers of hospital-based utilization. RESULTS: The MCL population consisted primarily of males (70.8%) and had a mean age of 66 years.  Of 35,762 visits 84.6% occurred in the outpatient setting. Infection (OR=7.4, p<.0001), fluid and electrolyte disorders (OR=6.3, p<.0001), plegia (OR=5.9, p<.01), myelosuppression (OR=5.2, p<.0001) and nutritional deficiencies (OR=3.3, p<.0001) were associated with inpatient admissions.  The most common complications of treatment included myelosuppression (21.7%), gastrointestinal issues (GI, 7.3%), infection (4.9%) and renal deficiency (4.8%).  Pharmacy (49.2%), room and board (12.8%), laboratory testing (10.2%), diagnostic services (7.8%), and surgery (5.8%) costs were the most common in this population.  When patients were admitted the average LOS was 8.3 days with an average cost of $18,291 and 5.0% in-hospital mortality rate.  During inpatient hospitalizations 55.0% received chemotherapy, 26.1% had a blood transfusion, 5.2% had a bone marrow biopsy, 4.4% had a stem cell transplant, 2.3% had hemodialysis and 1.5% had radiotherapy.  Nutritional deficiencies (IRR=1.55, p<.0001), plegia (IRR=1.51, p<.0001), infection (IRR=1.46, p<.0001), myelosuppression (IRR=1.34, p<.0001) and GI (IRR=1.3, p<.0001) were associated with longer LOS. Readmissions occurred within 30 days for 28.6% of inpatient admissions with 41.4% of readmissions having maintenance chemotherapy or radiotherapy as the primary diagnosis. CONCLUSIONS: MCL patients primarily use outpatient services.  Inpatient services are required to treat complications of treatment such as myelosuppression and infections as well as to provide follow-up treatments and care.