In order to evaluate the effect of peppermint and faba bean intercropping patterns, a field experiment was carried out as a randomized complete blocks design (RCBD) with 9 treatments and 3 replications at the Faculty of Agriculture, University of Maragheh, Iran during 2015 growing season. Treatments included sole planting of peppermint and faba bean and intercropping patterns with ratios of 1:1, 1:2, 2:1, 2:3, 3:2, 1:3 and 3:1 (peppermint: faba bean). The highest number of pods per plant (5.4), seeds per pod (3.7) and 100-seed weight (118.4 g) were achieved in the ratio of 2:3. The highest seed yield of faba bean per occupied unit of land when the latter species were planted with the ratios of 2:3 (268.3 g m^-2) and 1:3 (250 g m^-2). The highest seed yield of faba bean per intercropped unit of land area was related to faba bean sole cropped (189.8 g m^-2) and 1:3 (187.5 g m^-2) cropping pattern. Also, the highest dry mass yield of peppermint per occupied unit of land area was obtained in the 2:3 treatment (629 g m^-2) with no significant difference with 3:2 and 1:3 treatments. The highest dry mass yield of peppermint per intercropped unit land area was observed in the peppermint sole cropped (320 g m^-2) and ratio of 3:2 (303 g m^-2) with no significant difference with 2:1, 2:3 and 3:1 cropping patterns. The highest peppermint essential oil percentage (2.15%) and essential oil yield (5.61 g m^-2) were related to 2:3 and 3:2 treatments. In all cropping patterns (except of 1:1 treatment), the LER value was higher than 1, while LER_s value was higher than 1 in 2:3, 3:2 and 1:3 treatments. The greatest value of LER_s (1.31) was achieved in 2:3 cropping pattern. In conclusion, based on faba bean seed yield, peppermint essential oil content and yield and LER_s, the ratio of 2:3 for peppermint:faba bean was superior to other treatments.