The advent of computers in psychological and educational measurement has led to the need for algorithms for optimal assembly of tests from item banks. This paper reviews optimal test assembly literature and introduces the contributions to this Special Issue. Four approaches to computerized test assembly are discussed: heuristic-based test assembly, 0-1 linear programming, network-flow programming, and an optimal design approach. Ap-plications of these methods to a variety of problems are examined, including IRT-based test assembly, classical test assembly, assembling multiple test forms, item matching, observed-score equating, constrained adaptive testing, assembling tests with item sets, item bank design, and assembling tests with multiple traits. A bibliography on optimal test assembly is provided.