This work describes the preliminary results of a tutoring program that provides personalized academic assistance to first-year undergraduates enrolled in introductory chemistry, physics and mathematics courses at Universidad Andres Bello (UNAB), in Concepción, Chile. Intervened courses have historically large enrolments, diverse student population and high failure rates. The evaluation of the program was performed in terms of the academic results and perception surveys collected from 377 voluntary students who participated in the tutoring program during the first semester of 2014. Results indicate that participant students accomplished better academic results in their chemistry, physics and mathematics courses, compared to non-participants. In addition, survey results revealed a positive perception about the tutoring program and evidence the tutor's dedication, disciplinary knowledge and ability to explain things easily as favorable qualities that contribute to learning.