Overall, children and adolescents diagnosed with dyslexia or ADHD show an increased risk for psychological and mental health problems, and dyslexia and ADHD tend to coexist frequently. Thus, the main objective of this study was to examine psychological and mental health problems in dyslexia. Participated 95 adolescents with dyslexia (DG), comorbid dyslexia + attention-deficit hyperactivity disorder, combined subtype (D + ADHD-CG), and a comparison group with typical development (TDCG). Self-reported measures of anxiety and depression, and parent and teacher versions of the Strengths and Difficulties Questionnaire (SDQ) were used. Self-reports of internalizing problems showed that adolescents in the GD and D + ADHD-CG groups had more depression and stated anxiety problems with a very high percentage above the clinical cut-off point than the CG. Both the parent and teacher reports showed that the DG and D + ADHD-CG groups obtained higher mean values and a higher number of adolescents above the clinical cut-off of internalizing, externalizing, and total problems than the TDCG. The comorbid D + ADHD-CG group had the highest internalizing and externalizing problems. In conclusion, our findings indicate that the internalizing and externalizing problems experienced by adolescents with dyslexia and comorbid ADHD should be recognized early and treated promptly by education professionals.