Measurement instruments of early childhood teachers' mathematical pedagogical content knowledge (MPCK) have to consider the special characteristics of early childhood teaching. Early childhood teaching includes some planned activities but in contrast to learning in school, it is often motivated and generated by situations which unfold spontaneously in play and everyday activities. Therefore, and to respect that early childhood teachers as experts in their field may fail to explain their knowledge explicitly but indeed show implicit knowledge in their daily work, a measurement approach related to concrete situations seems to be suitable. While there are qualitative MPCK interview-instruments following this approach, there is still a lack of standardized instruments suitable for large-scale studies. As a first proposal to approach this gap, we developed a paper-pencil test with multiple-choice items measuring MPCK, and respecting early childhood teachers' implicit knowledge. The test is based on descriptions of four typical kindergarten situations. Linked to each situation, we developed a set of items measuring professional knowledge concerning mathematical abilities of children and two multiple-choice items measuring professional knowledge of adaptive mathematical learning activities. The 39 items were piloted with a sample (N = 149) of pre- and in-service early childhood teachers. The results show validity evidence related to the "test content," "response processes," the "internal structure of the test," as well as "convergent evidence." Therefore, the test provides a suitable first approach to measure early childhood teachers' MPCK, while addressing their implicit knowledge.