[eng] Objective. The objective was to examine the longitudinal correlates of sluggish cognitive tempo (SCT) and ADHD-Inattention (IN) dimensions with mothers' and fathers' ratings of Spanish children. Method. Mothers and fathers rated SCT, ADHD-IN, ADHD-hyperactivity/impulsivity (HI), oppositional defiant disorder (ODD), depression, academic impairment, and social impairment on three occasions (twice in first grade year [6-week separation] and once in the second grade year [12-months after the first assessment]) in Spanish children (758, 746, and 718 children at the three time-points with approximately 55% boys). Results. The results showed that (1) higher levels of SCT from earlier assessments predicted higher levels of depression, academic impairment and social impairment at assessment three after controlling for ADHD-IN at earlier assessments, (2) higher levels of ADHD-IN from earlier assessments predicted higher levels of depression, academic impairment and social impairment at assessment three after controlling for SCT at earlier assessments, (3) higher levels of ADHD-IN from earlier assessments predicted higher levels of ADHD-HI and ODD at assessment three after controlling for SCT from earlier assessments, and (4) higher levels of SCT from earlier assessments either showed no unique relationship with ADHD-HI and ODD or predicted lower levels of ADHD-HI and ODD at assessment three after controlling for ADHD-IN from earlier assessments. Conclusions. Initial evidence is provided of SCT's unique longitudinal relationships with depression and academic/social impairment and different longitudinal relationships with ADHD-HI and ODD relative to ADHD-IN, thus adding to a growing body of research underscoring the importance of SCT as distinct from ADHD-IN.