Purpose: People with Williams syndrome (WS, n = 20, CA = 12.5, MA = 8.9) have strong verbal short-term memory but challenged verbal long-term memory. This study aimed to evaluate the memory abilities of people with WS and examine the possibility of improving their memory performance. Methods: Twelve navigations completed the study. Fourteen indexes were used for each navigation. Controls matched in chronological age (CA, n = 20, mean age = 12.5), mental age (MA, n = 20, mean age = 8.8), 5th graders (n = 20, mean age = 10.3), and college students (CS, n = 20, mean age = 20.2) were recruited. Results: The WS group was slowest and erred more in completing tasks than the CA and MA groups. The error patterns revealed group differences in the number of extra items purchased and missed correct items. The 5th graders erred more than the CS on extra items purchased; the CA group erred more than the CS and the 5th graders on missed correct items. The WS group erred more than the CA and MA groups for incorrect items purchased, extra items purchased, missed correct items, and incorrect types purchased. The error patterns yielded replacements and confusion. Semantic features attributed to atypical processing during navigation have emerged in people with WS. Conclusion: These findings suggest that people with WS have developmental disorders in verbal long-term memory. The current study serves as a foundation for future interventions in people with WS.