Background Sleep impairment, fatigue, and anxiety are common conditions in cancer survivors. Small studies suggest mindfulness-based interventions may be helpful for cancer-related fatigue. Objective To evaluate mindfulness-based cancer recovery (MBCR) for cancer survivors who are recovering from chemotherapy or radiation therapy. Methods 42 cancer survivors who were within 6 months of completion of chemotherapy or radiation were randomized 2:1 to 8 weekly MBCR classes (n = 28) or wait-list control (n = 14). The Pittsburgh Sleep Quality Index (PSQI), Functional Assessment in Cancer Therapy-Fatigue (FACT-F), and 20-item State-Trait Anxiety Inventory (STAI) were used to assess sleep, fatigue, and anxiety at baseline (time of enrolment), at 2 months (on completion of the MBCR course), and 4 months (2 months after completion of the course). 32 of 42 participants participated in an optional blood draw to assess immune function. Results 79% of the MBCR group attended at least 7 of the 9 MBCR sessions. At the 2-month assessment, sleep quality (PSQI, range 0-21, <5 = poorer sleep quality) in the MBCR group improved from the baseline 8.9 to 6.4, compared with the wait-list group (baseline 7.2 to 7.6); and at 4 months after course completion, it was 6.1 compared with 7.8, respectively (P = .03). There was a non-statistically significant improvement in fatigue (FACIT-F, P = .19). There was a trend toward improvement in the anxiety scores (STAI, range 20-80, higher score = greater anxiety) in the MBCR group compared with the wait-list group at 2 months (31.8 vs 39.4, respectively; P = .07) and 4 months (32.8 vs 40.7; P = .10). Immune function measures were not statistically significant. Limitations It is possible the psychological support of being in contact with a facilitator and/or other cancer survivors had a beneficial effect in the outcomes of those in the MBCR group. Conclusion MBCR has a high compliance rate and results in sustained improvements in sleep quality, fatigue, and anxiety. MBCR may be useful for cancer survivors struggling with sleep, fatigue, and anxiety.