Malnutrition is common in pulmonary tuberculosis (TB), and may impair survival. The objective of this study was to assess effects of multi-vitamin/mineral (MVM) and zinc (Zn) supplementation during TB treatment on mortality. Patients diagnosed with sputum-positive pulmonary TB in Mwanza, Tanzania, were randomised, using a two-by-two factorial design, to Zn (45 mg) or placebo, and MVM (vitamins A, B, C, D, E, and selenium and copper) or placebo. Survival status was ascertained at the end of the 8-month TB treatment and supplementation period. Of 499 TB patients, 213 (43 %) had HIV. The mean weight gain at 7 months was 6.88 kg (95 % CI 6.36, 7.41). Zn and MVM combined, but neither alone (interaction, P=0.03), increased weight gain by 2.37 kg (95 % CI 0.91, 3.83), irrespective of HIV status. Survival status at 8 months was determined for 422 patients (84.6 %), of which fifty-two (12.3 %) had died. Among fifty-two deaths, there were no effects of MVM (relative risk (RR) 0.73; 95 % CI 0.43, 1.23) and Zn (RR 0.76; 95 % CI 0.46, 1.28). However, among HIV co-infected patients, marginally significant effects of both MVM (RR 0.60; 95 % CI 0.34, 1.05) and Zn (RR 0.63, 95 % CI 0.37, 1.08) were seen, and MVM and Zn combined reduced mortality (RR 0.29; 95 % CI 0.10, 0.80; interaction ratio 0.52). In conclusion, supplementation with MVM, including Zn, during treatment of pulmonary TB may reduce mortality in those co-infected with HIV. A randomised trial of the effect of the combined intervention used in this study should be conducted in a different setting to confirm the finding.