The Measure of Processes of Care (MPOC) is a questionnaire for parents used to evaluate the behaviours of healthcare providers. We applied its 20-item version (MPOC-20) to explore the associations between parental evaluation of processes of care and child, parent and family characteristics in Slovenia. A novelty of our approach was the emphasis on the role of a key person. Parents of 235 children who were admitted as inpatients or outpatients of six institutions (hospitals and health centres) because of chronic illness or disability participated in the study. Parents were asked to fill in a general questionnaire on several characteristics of the child, child's health problems, the family and the therapy programmes, and MPOC-20. Univariate associations of the five MPOC-20 scale scores with child, parent and family characteristics were tested first. Multiple linear regression was used for modelling scale scores in relation to child, parent and family characteristics. The analyses singled out availability of a key person as the factor most consistently and unequivocally influencing parental satisfaction. We also found a general positive effect of male sex of the child on the MPOC-20 scores. Neither the present age of children nor age at the onset of health problems was found to be associated with MPOC-20 scores. We found no notable association of the number of health problems with the MPOC-20 scores, but observed clear differences when comparing parental satisfaction with processes of care between different participating institutions.