This issue contains a selection of papers presented at CLAIO XIII, the 13th Latin– Iberian–American Conference on Operations Research and Systems, held in Montevideo, Uruguay, on November 27–30, 2006. CLAIO XIII was organized by the University of the Republic of Uruguay (UdelaR) and the Latin–Iberian–American Association of Operations Research Societies (ALIO). The event was sponsored by IFORS (International Federation of Operational Research Societies), the Uruguayan National Program for the Development of Basic Sciences (PEDECIBA), the Council of Scientific Research (CSICUdelaR), and the Council of Education (CSE-UdelaR). The CLAIO conferences, held biannually since 1982, highlight recent developments in theory, models, algorithms, and applications of operations research in its broadest sense. In particular, this issue is devoted to those works that represent successful applications of research on heuristic methods. These include contributions that address complex problems driven by real-world applications and works that present significant advances to the state-of-the-art on difficult optimization problems. Among the more than 300 papers presented at the conference, 17 were submitted to this special issue. Each submission was peer-reviewed under the journal’s criteria for scientific merit. The selected articles cover application areas such as optimal design of motorcycle frames, assembly line balancing, and hospital waste manage-