The purpose of the study was to examine the developmental pathways of elite youth swimmers. Swim-related developmental activities of elite and sub-elite youth swimmers were examined. Fifteen elite (8 males; 7 females) and 15 subelite (5 males; 10 females) youth swimmers were recruited for the study. A semistructured questionnaire was used to record retrospectively the hours engaged in swim-related activities (i.e., structured and unstructured activities) from beginning of career. No significant differences were found for swim-related developmental milestones for both elite and sub-elite swimmers. Overall, the elite swimmers accumulated more hours in swim-related activities than the sub-elites between 6-15 years of age. Although the former accumulated more hours in both structured and unstructured swimming activities between 6-12 years of age, no significant differences were found between the groups. However, the elite swimmers accumulated significantly more hours in structured swimming activities between 13-15 years of age. Both groups had analogous developmental pathways during childhood but the onset of adolescence led to different outcomes. The increased hours in structured practice during adolescence is suggested to have influenced the level of attainment in swimmers. Incremental amount of training at certain age period is critical in developing optimum performance in sports.