Abstract: Objective To explore the influence of dietary intervention on the treatment outcome of new smear positive pulmonary tuberculosis (PTB) patients with malnutrition. Methods 60 new smear positive PTB patients with malnutrition admitted in our hospital from January 2013 to December 2013 were in control group, and 60 new smear positive PTB patients with malnutrition admitted in our hospital from January 2014 to December 2014 were in intervention group, the patients of both groups received anti-TB therapy. Routine health education was conducted for patients in control group during their stay in hospital. Patients’ nutritional assessment was performed within 24 hours of admission, two weeks after admission and when they left the hospital in intervention group, the individual energy standard of the patients was adjusted and dietary intervention was conducted by the doctors and nursed who received nutrition knowledge training by special monitoring group on nutrition. The reexamination of sputum and chest radiography of the patients in the two groups were performed at the enrollment, after 2 months’ treatment, 5 months’ treatment and 6 months’ treatment, in order to get the information of sputum conversion, the lesion changes and treatment outcome. Results When the patients were discharged from the hospital, the patients with malnutrition accounted for 20.00% (12/60) in the intervention group after treatment and intervention, which was significantly less than that (65.51%, 38/58) in the control group (χ2=25.023, P﹤0.01). The degree of satisfaction in the intervention group reached up to 96.67% (58/60), which was higher than the control group (77.58%, 45/58), and the difference was statistically significant (Z=9.72，P﹤0.05). The patients in the intervention group whose lesions were significantly absorbed accounted for 51.67% (31/60), which was obviously higher than the that in the control group (31.03%, 18/58)(χ2=37.168, P﹤0.01). The sputum negative conversion rate of the patients in the intervention group was 83.33% (50/60), and that in the control group was 53.44% (31/58), with statistically significant difference (χ2=12.237，P ﹤0.01). The rate of no changes in lesion in the intervention group (6.7%, 4/60) was significantly less than the that in the control group (29.3%, 17/58)(χ2=10.336, P﹤0.01). Conclusion Dietary intervention on smear positive PTB patients at the beginning of treatment can evidently correct the situation of malnourish, and it can also improve the cure rate of the patients.