This study investigates children’s vocabulary knowledge in Finnish Sign Language (FinSL), specifically their understanding of different form-meaning mappings by using a multi-layered assessment format originally developed for British Sign Language (BSL). The Web-based BSL-VT by Mann (2009) was adapted for FinSL following the steps outlined by Mann, Roy, & Morgan (2016) and piloted with a small group of deaf and hearing native signers (N=24). Findings showed a hierarchy of difficulty between the tasks, which is concordant with results reported previously for BSL and ASL. Additionally, the reported psychometric properties of the FinSL-VT strengthen previous claims made for BSL and ASL that the underlying construct is appropriate for use with signed languages. Results also add new insights into the adaptation process of tests from one signed language to another and show this process to be a reliable and valid way to develop assessment tools in lesser researched signed languages such as FinSL.