Leisure activities are widely used in research to predict important outcomes, but the existing studies use different classification schemes and apparently rely on the intuition of the researcher to classify activities. The goal of the current study was to use the Holland RIASEC personality system to empirically classify activities using a sample of older adults. Nine activity scales were identified. The correlation of these activity scales with the Holland system showed that they could be reliably classified; further, multidimensional scaling suggested that the pattern of relationship could be interpreted in terms of the RIASEC hexagon. The overall findings suggest that Holland's RIASEC system may offer a useful way to classify many activities. (Contains 5 tables and 1 figure.)