This research aims to define the most popular sports in a sample of schoolchildren, and to relate sports practice levels with the level of effort implicated, the kind of leisure-Time activities, and the notion about Physical Education (PE). A descriptive and cross-sectional study was conducted on a sample of 818 students of third cycle of Primary Education from the province of A Coruña (Spain). Gender representation was 52% for boys and 48% for girls, with age range between 10 and 13 years old (M = 11,17; SD = 0,44). The instrument employed was an Ad-Hoc questionnaire for recording sociodemographic factors and sports-related variables. Results show that one out of ten schoolchildren does not practice any sport, whilst collective sports with contact, mainly played in a federated way, are the most practiced. Football and water sports were the most popular, whereas track and field and cycling were the least practiced. Furthermore, the time spent on sports practice was positively related with leisure-Time sports and perceived aptitude towards PE, and negatively correlated with digital leisure time. The level of effort involved in sports was negatively correlated with sport leisure time, notion of PE, and perceived aptitude towards PE. Finally, sports leisure time was found to have a negative relation with academic and digital leisure times, as well as a positive relation with the notion of PE and perceived aptitude towards PE. © Federación Española de Asociaciones de Docentes de Educación Física (FEADEF).