Attention-deficit/hyperactivity disorder (ADHD) often co-occurs with reading disability. A cross-sectional study in an Italian-speaking, nonclinical sample was conducted in an attempt to document the existence of an early association between reading difficulties (RD) and ADHD behaviours. We recruited a sample of 369 children in their first year at primary school. Of the sample, 8.4% displayed RD; 7.0% had ADHD; 3.5% presented both RD and ADHD behaviours; 50% of the children with ADHD displayed RD; 41.9% of those with RD displayed ADHD behaviours. Low socioeconomic status was associated with a fourfold increased probability of displaying RD (odds ratio?=?3.98), but not ADHD behaviours. In this nonclinical sample, we detected an early association between ADHD behaviours and RD. A key role in this association may be played by inattention symptoms, which occurred with significantly increased frequency also in the group presenting only RD.