Multiple factors may contribute to the decision to initiate methylphenidate treatment in children such as maternal sociodemographic factors of which relatively little is known. The objective was to investigate the association between these factors and methylphenidate initiation. The study population included 4243 children from the Generation R Study in the Netherlands. Maternal sociodemographic characteristics were tested as determinants of methylphenidate initiation through a time-dependent Cox regression analysis. Subsequently, we stratified by mother-reported ADHD symptoms (present in 4.2% of the study population). When ADHD symptoms were absent, we found that girls (adjusted HR 0.25, 95%CI 0.16–0.39) and children born to a mother with a non-western ethnicity (compared to Dutch-Caucasian) (adjusted HR 0.42, 95%CI 015–0.68) were less likely to receive methylphenidate. They were more likely to receive methylphenidate when their mother completed a low (adjusted HR 2.29, 95%CI 1.10–4.77) or secondary (adjusted HR 1.71, 95%CI 1.16–2.54) education. In conclusion, boys and children born to a mother of Dutch-Caucasian ethnicity were more likely to receive methylphenidate, irrespective of the presence of ADHD symptoms.