Effects of environmental exposures in utero and in the first years of life on early life health and development is a growing research area with major public health implications. The main aim of this work has been to provide an overview of the next step of the Polish Mother and Child Cohort Study (REPRO_PL) covering exposure, health and neurodevelopment assessments of children at 7 years of age. Details regarding methodology of the follow-up of the children are crucial for cross-cohort collaboration and a full understanding of the future research questions. Phase III of the REPRO_PL cohort covers a follow-up of 900 children at the age of 7 years old. The questionnaire filled in by the mothers is composed of: socio-demographic, child exposure and home environment information, nutritional status and health data. In the case of 400 children, environmental (including collection of urine, saliva and buccal cells), health status and psychomotor assessments are performed. Health and development check consists of physical measurements, child health status assessment (including lung function tests, skin prick testing, an interview/examination by an allergist) and psychomotor development tests (the Strength and Difficulties Questionnaire and the Intelligence and Development Scales). The results of the study will become available within the next few years. Extension of the REPRO_PL cohort with examinations of children at the age of 7 years old may provide a better understanding of the relationship between environmental and lifestyle-related factors and children’s health and neurodevelopment; and may further strengthen scientific base for policies and interventions promoting healthy lifestyle. Int J Occup Med Environ Health 2016;29(6):883-893