Purpose - The aim of this paper was to assess information needs and information seeking behaviour of parents and caregivers of children with mental illness at the Kilimanjaro Christian Medical Centre (KCMC) in Tanzania. The study mainly assessed the information needs of parents and caregivers of children with mental illness, their preferable sources of health information, and their constraints on information seeking. Design/methodology/approach - A case study research design was used in this study,where 168 structured questionnaires were distributed to parents and caregivers of children with mental illness at the Neurological Pediatrics Outpatient Clinic (NPOC) of Kilimanjaro Christian Medical centre (KCMC). The rate of response was 89.3%. Findings - The study found that health information needs of parents and caregivers were mainly associated with health care (for example, nutrition, treatment), and health education. Parents and caregivers of children with mental illness used the internet as the main source of information about their children's health, which was followed by printed books and television. Health information seeking behaviour appeared similar across gender categories, but there were differences on the use of print and electronic information sources according to age and level of education. The main factors that hindered access to health information included low level of education, lack of funds and health information illiteracy. Practical implications - The paper provides practical suggestions that would facilitate information seeking and use among parents and caregivers of children with mental illness in Tanzania and other countries with similar conditions. Originality/value - Previous studies on the topic are scanty and, therefore, the paper provides important insights into the information needs and information seeking behaviour of parents and caregivers of children with mental illness in a developing country setting.