The present study examined associations between social, emotional, and behavior (SEB) problems in toddlerhood and social and emotional strengths and difficulties at eight years of age. In addition, we were interested in associations between parental worry about the child´s psychosocial and language development in toddlerhood and social and emotional strengths and difficulties at age eight years. Participants were 554 children (52.7% boys) and their parents, involved in a longitudinal study with annual assessments. Parents rated children´s social-emotional competence at eighteen months, using the Brief Infant-Toddler Social and Emotional Assessment (BITSEA), and again at eight years, using the Strengths and Difficulties Questionnaire (SDQ). Parental age, education, socio-economic status and income were applied as control variables. Sex effects were also investigated. Early SEB problems predict some, but not all, aspects of later SE development. While competence delay was associated with less prosocial behavior, SEB problems predicted only hyperactivity and conduct problems, not later peer problems or emotional symptoms. Parental worry, especially about child language development, was an important indicator of later SEB problems. Based on our study results, actions and interventions aiming to support children´s SE development throughout childhood should take into consideration its differentiated form and associations. Furthermore, parental worry about children´s language development should not be ignored when diagnosing SEB problems and competence delays.