The research reported in this paper evaluated the weaknesses of an existing child patients' garment and generated ideas to develop a new practical garment to be used in a hospital environment in Hong Kong, China. The design procedure was based on the principles of product development, with the aim of achieving functions on physical and psychological aspects of the child patients during hospitalisation. The background of the investigation is one in which child patients are unwilling to wear the existing hospital garment. From the literature, a comfortable garment can be assessed by its physical and psychological functions. Accordingly, a hospital garment should offer child patients positive medical and perceptional comfort. Qualitative information was obtained from observation and focus-group discussion. It was decided that the design criteria of the existing garment, including style, size, fasteners, fabric, and colour, should be evaluated through obtaining quantitative comments from child patients, nurses, and paediatricians in a questionnaire survey. The results showed that most of the respondents had negative attitudes towards the existing design criteria, and these led to their reluctance to wear or use the hospital garment. Further, requirements on physical and psychological aspects of the garment were significantly different among different respondent groups, and thus useful ideas could be generated from each group; this paved the way to design a practical garment with optimum functions.