Psychological professionals in Japan's child welfare system perform diverse roles, including protecting children from maltreatment and supporting those with disabilities. Psychological assessments are crucial in these contexts because they offer valuable insights into children's cognitive, emotional, and behavioral functioning. However, the wide range of available tools and frequent updates of test versions have left the actual patterns of use—and the challenges faced by practitioners—unclear. This study examined how psychological professionals in child welfare services utilize assessments, the challenges they encounter, and their training needs, to inform professional development. A questionnaire survey was administered to 20 psychologists employed in local government child welfare offices. Participants evaluated 13 commonly used assessments for children, including intelligence and personality measures. Using a five-point Likert scale, they rated four domains: (a) administration accuracy, (b) appropriateness of interpretation, (c) adequacy of feedback, and (d) effectiveness of information sharing with families and stakeholders. Participants also reported their professional experience and provided open-ended responses on particularly important assessments and the reasons behind their selections. Mean differences were examined using analysis of variance. Respondents reported an average of 5.95 years of professional experience (range = 1-15, SD = 4.73). The Wechsler Intelligence Scale for Children and Tanaka-Binet Intelligence Test were most frequently identified as essential for understanding and supporting children. Simultaneously, the Rosenzweig Picture-Frustration Study was valued for assessing interpersonal and behavioral difficulties. Although administration accuracy was generally high, difficulties persisted in providing feedback and communicating results to families and stakeholders. These findings suggest that while test administration skills are relatively well-developed, targeted training is necessary to enhance the application of assessment results and to strengthen collaboration with families and other stakeholders.