Resumen: Handgrip strength is a simple measure of general muscle strength and is related to functionality in people with intellectual disabilities. The objective of this research was to describe the normative values of absolute and relative handgrip strength in children, adolescents and adults according to sex. The sample was made up of 264 schoolchildren (n = 168 men) belonging to five special education schools in Santiago of Chile. The results show higher levels of absolute handgrip strength in males compared to females. The maximum peak of the absolute manual handgrip is reached in females in adolescence with a decrease in adulthood. Relative handgrip strength levels are similar in boys and girls. In females, the relative handgrip strength is similar in childhood and adolescence. Relative handgrip strength declines in both sexes from adolescence to adulthood. The reference values of this study can be used by professionals in the areas of health and education as a guide for interpretation, monitoring and follow-up of Chilean schooled people with intellectual disabilities.