The major role of self-directed learning (SDL) in a successful learning at distance education has been confirmed by various studies. Although learners pass General English courses before studying any ESP courses at distance education of Iran, they usually lack the preliminary skills for independent language learning. The current study aimed to explore the effect of self-directed training (SDT) on ESP learners’ self-directed learning readiness (SDLR). Eighty-six B.A students (19 male and 67 female) studying English for Economy and Management at Tabriz Payam-e-Noor University participated in this study. A demographic questionnaire and Guglielmino’s (1978) self-directed learning readiness scale (SDLRS) were implemented to select the participants of the control and experimental groups. The experimental group was provided with SDT in three different stages a) an introduction to SDL, b) SDT workshop, and c) SDT pamphlet. Then, a post-test of SDLRS was given to the two groups. ANCOVA was applied to analyze the data. The results revealed that SDT could enhance ESP learners’ SDLR. The findings imply that an appropriate training is needed to improve learners’ SDLR. Higher levels of SDLR can contribute to a successful ESP learning at Payam-e-Noor University in Iran.