This study will examine the effectiveness of MabThera therapy added to a standard chemotherapy regimen for the treatment of previously untreated chronic lymphocytic leukemia (CLL). Patients who have received a single prior MabThera plus chemotherapy treatment are eligible. The overall response rate of patients treated for approximately 5 months (as per current label guidelines) will be analysed according to various factors (i.e., age, concurrent treatment, and chromosomal abnormalities).

Inclusion Criteria:

• Diagnosed with first-line CLL having received only 1 cycle of MabThera chemotherapy
• aged >/= 18 years

Exclusion Criteria:

• Pregnant or breast-feeding
• Receipt of an investigational drug within 30 days prior to entering the study

Patients with untreated chronic lymphocytic leukemia (CLL)