Autistic disorder is characterized by severe disturbances of social relatedness, impairments in language and communication, and restricted, repetitive, and stereotyped patterns of behaviors. Accumulated data strongly support the notion that genetic factors, as yet undetermined, play a significant role in the etiology of this syndrome. As genetic research in autism is still exploratory, full genomewide searches have been performed to localize susceptibility regions within the genome. Methods and results from the four first full-genome scans published to date (IMGSAC, 1998a; Philippe et al., 1999; Risch et al., 1999d; Barrett et al., 1999) are considered in this review. The four sets of multipoint linkage results are grouped in a single figure to facilitate comparisons among the four studies and with previous or future results. Although findings must be considered with caution because LOD score values do not reach the threshold for significant linkage, a region of approximately 50 cM on the long arm of chromosome 7 appears to play a role in the etiology of autistic disorder.