Inclusion Criteria:

- adult patients, >=18 years of age;

- histologically confirmed grade 1, 2 or 3a follicular non-Hodgkin's lymphoma;

- patients who have received adequate (>=8 cycles) induction therapy with MabThera as
first line treatment, or treatment for relapsed disease;

- demonstrated partial or complete response to induction therapy.

Exclusion Criteria:

- stable or progressive disease after most recent induction therapy;

- transformation to high grade lymphoma;

- patients with prior or concomitant malignancies, except non-melanoma skin cancer or
adequately treated in situ cancer of the cervix.