One of the disorders that most affects school performance is Attention Deficit Hyperactivity Disorder (ADHD). The criteria established by DSM distinguish three subtypes: inattentive, hyperactive-impulsive and combined. However, the expression of this disorder can be altered by its association with other disorders such as anxiety. The main goals of this study were to determine whether different patterns of attention (selective and concentration) and anxiety (state and trait anxiety) emerge from ADHD subtypes, and analyze how anxiety predicts the performance of students with ADHD in a selective attention task. The sample was made up of 220 children (6-12 years) divided into four groups: control group ( = 56), inattentive subtype ( = 54), hyperactive-impulsive subtype ( = 53), and combined subtype ( = 57). The results indicated that the groups differed significantly in the attention variables, and in state and trait anxiety. Multiple group comparisons revealed that the combined subtype exhibited higher trait anxiety, whereas the inattentive subtype showed more state anxiety. Additionally, trait anxiety predicted the students' performance in the concentration variable of the attention task. These results suggest a novel path of significant interest concerning objective and reliable diagnostic assessment of ADHD.