A sample of 1,209 university students from 3 countries (Italy, New Zealand, and USA) completed a 24-item self-report measure for ADHD symptoms in a study at Lehigh University, Bethlehem, PA. Factor analyses supported a diagnosis of ADHD, according to the bidimensional classification of DSM-IV, in the US and New Zealand samples, but less in the Italian students. The percentages of self-reported ADHD subtypes in US, Italian, and NZ students were as follows: In men, inattentive, 6, 7.7, and 8.1, respectively; H/I, 14, 18.5, and 10.8; Combined, 7.4, 11.1, 10.8. In women, inattentive, 3.9, 9.0, and 9.8; H/I, 13.8, 25.8, 18.4; Combined, 6.9, 8.3, and 9.2, respectively. Italian students reported more inattention and H/I than US students. NZ students had significantly more inattentive symptoms than US students, especially women.