The main challenge of understanding Sharia in the West is its undefined nature. This contradicts the ease with which the term is used in public and political discourse, but also in the legal domain, which prides itself on its precision in terminology. This article addresses the question: What is the Sharia that Muslims in the West practice? To this end, a model is presented that provides tools to describe the complex interaction between Sharia, as practiced by Western Muslims, and their Western environment, and elucidates the ongoing dialectic of this interaction. The model further shows how Western Muslims adopt and adapt Sharia by manoeuvring between their specific needs in the Western context and the conditions set by that context. From a Western perspective, the model shows that issues of Sharia are usually discussed in legal terms, while most controversies are not legal but cultural in nature.