A theoretical discussion is presented of the design features that have been incorporated into a multipass cell appropriate for use in laser molecular‐beam experiments. A detailed description of the cell in two dimensions is given, and this is later expanded to highlight the problems of alignment in three dimensions. A prototype cell, constructed using the guidelines presented here, has demonstrated that 31 passes through a molecular beam can be easily achieved. Computer simulations suggest that the optimum potential of the cell is ≊101 passes. The fact that the position of the emergent laser beam is clearly defined makes the cell particularly useful for the purposes of studying absorption spectra.