Research on ASD in infancy has provided a rationale for developing screening instruments for children from the first year of life to age of 18 months. A comprehensive literature search identified candidate screening tools. Using methodological probe questions adapted from the Quality Assessment of Diagnostic Accuracy Studies (QUADAS), two Level 1 and three Level 2 screening instruments were reviewed in detail. Research evidence conclusions were that instrument development was in beginning phases, is not yet strong, and requires further development. Clinical recommendations were to continue vigilant developmental and autism surveillance from the first year on but to use the screening instruments per se only for high-risk children rather than for population screening, with considerations regarding feasibility for individual settings, informing caregivers about strengths and weaknesses of the tool, and monitoring new research.