A model is proposed of the effect of parallelism on meter. It is wellknown that repeated patterns of pitch and rhythm can affect the perception of metrical structure. However, few attempts have been made either to define parallelism precisely or to characterize its effect on metrical analysis. The basic idea of the current model is that a repeated melodic pattern favors a metrical structure in which beats are placed at parallel points in each occurrence of the pattern. By this view, parallelism affects the period of the metrical structure (the distance between beats) rather than the phase (exactly where the beats occur). This model is implemented and incorporated into the metrical program of D. Temperley and D. Sleator (1999). Several examples of the model's output are presented; we examine problems with the model and discuss possible solutions.