It is well-established that at old age there is a significant decline in muscle strength. Reference values for muscle strength might be useful for assessment of muscle impairment and of physiological adaptations. However, it is still unclear whether gender affects the rate of decline. Therefore, the aim of this study is to investigate the effect of gender and age on handgrip strength and to establish reference values for this variable. Reviewing medical charts collected from 1994 to 2005, a convenience sample of 2,648 subjects (1,787 men and 861 women), aged between 18 and 90 years, was obtained. Our results show higher handgrip strength for men compared with women (36.8 +/- 0.20 vs. 21.0 +/- 0.18 kg; p < 0.001). The regression analysis with a quadratic model shows that aging accounts for 30% of the variance in handgrip strength (r(2) = 0.30; p < 0.001) in men and 28% (r(2) = 0.28; p < 0.001) in women. In addition, the bent linear regression with multiple regressors show that a faster decline in handgrip strength occurs at the age of 30 years for men and 50 years for women. We conclude that handgrip strength decline with age differs between genders, making useful the existence of distinct male and female normative age group data.