The objective of this study is to explore the association between maternal somatic anxiety in pregnancy and hyperactivity symptoms and ADHD diagnosis in children. Data from the Avon Longitudinal Study of Parents and Children cohort were used to examine the association between somatic anxiety symptoms in pregnancy measured with five items of the Crown-Crisp Experiential Index, ADHD diagnosis in children at 7.5 and 15 years (obtained with the Development and Well-Being Assessment-DAWBA) and hyperactivity at 4 and 16 years (measured with the Strengths and Difficulties Questionnaire hyperactivity subscale-SDQ). Maternal somatic anxiety was associated with ADHD diagnosis at age 7.5 [crude OR = 1.87 (95% CI = 1.21–2.91)], adjusted model [OR = 1.57 (95% CI = 0.99–2.48)]. There was no evidence of association with ADHD at 15: crude OR = 2.27 (95% CI = 0.90–5.71), adjusted OR = 1.65 (95% CI = 0.63–4.35). An association was found at 4 and 16 with the SDQ hyperactivity subscale: crude OR at 4: 1.70 (95% CI =1.37–2.11), adjusted OR = 1.34 (95% CI = 1.07–1.69); crude OR at 16: 1.95 (95% CI = 1.47–2.58), adjusted OR = 1.62 (95% CI = 1.21–2.17).Thus, there was evidence for an association between maternal somatic anxiety in pregnancy and increased hyperactivity symptoms (SDQ) at 4 and 16. There was no association with ADHD diagnosis.