The block design task (BDT) is a visuospatial measure that individuals with Williams syndrome (WS) perform poorly on. However, it is unclear what underlies their impaired performance. This study investigated whether poorer performance is a result of visuospatial difficulties, executive function (EF) difficulties, atypical looking strategies, or a combination of these. Eleven individuals with WS participated alongside mental age (MA)- and chronological age (CA)-matched control groups. Eye movements were recorded while they took the BDT. Dwell times and visits to areas of interest in WS differed from CA, but not MA, groups. Findings suggest that BDT abilities of individuals with WS are delayed, but not atypical. Delays result from visuospatial and attention-switching difficulties rather than atypical looking strategies.