Background: Assessing the speech production of multilingual children is challenging for speech-language therapists (SLTs) around the world. Scientific recommendations to improve clinical practice are available, but their implementation has mostly been described in studies from English-speaking countries. Aims: This survey aimed to describe the perspectives and practices of SLTs in assessing the speech production of multilingual children in French-speaking Belgium. Methods & Procedures: An online survey was completed by 134 SLTs in French-speaking Belgium. Outcomes & Results: SLTs predominantly used norm-referenced assessment approaches, which are not recommended for use with multilingual children, and lacked necessary training and resources to implement recommended practices in the assessment of speech production of multilingual children. The shift towards more appropriate practices with multilingual children seems to be in its infancy among SLTs in French-speaking Belgium. Some challenges identified by the SLTs were common to those in other countries and languages, such as the difficulty to distinguish between speech differences and speech disorders. Other challenges were specific to the French language and/or the Belgian context, such as the lack of appropriate tools in French. Conclusions & Implications: Action is required to improve clinical practice in assessing the speech production of multilingual children in French-speaking contexts: better training for SLTs regarding linguistic diversity, more implementation research in the field of SLT, and advocacy for linguistic diversity with decision makers.