Girls' underachievement in school science as compared to boys' has been widely documented in many studies. The performance of 170 boys and 107 girls, who were randomly picked from their eighth-grade classes, were compared for three problem-solving practical tasks. These tasks involved students in carrying out hands-on investigations and reporting on them. Particular care was taken to ensure that the boys and girls involved in the study were matched for attitude, aptitude and prior knowledge. For the global performance in such tasks, the study found little evidence to show that girls were underperforming compared to boys. There was a distinct preference, however, by girls for content familiarity. In fact, under situations of content familiarity, girls did better than boys in several of the constituent processes/integrated process skills involved in the practical tasks provided. These findings have important implications on how teachers should plan in connection with open-ended practical tasks.