A Phase I interventional Clinical Trial was performed with a potential tuberculosis vaccine, based on detoxified cellular fragments of M. tuberculosis, named RUTI. The objective was to evaluate the safety profile and T-cell immune responses over a 6-month period following subcutaneous inoculation. The double-blind, randomized and placebo-controlled trial was conducted in healthy volunteers, all recruited at one site. RUTI, at each of the four tested doses, starting from 5microg and going up to 200microg, and placebo were inoculated to groups of 4 and 2 volunteers respectively, consecutively. RUTI appeared to be well tolerated as judged by local and systemic clinical evaluation, though vaccine dose dependent local adverse reactions were recorded. T-cell responses of blood lymphocytes to PPD and a number of antigen subunits were elevated, when compared with controls subjects. These results support the feasibility of future evaluation, to be targeted at subjects with latent tuberculosis infection (LTBI).