Food barley and lupine are food crops often traditionally grown in intercropping in north western Ethiopia. But, there is no any documented information about the optimum seeding rate and time of lupine intercropping with barley in Gozamin District northwestern Ethiopia. Hence, a field experiment was conducted on seeding rate and time of intercropping of lupine with barley in Gozamin District to determine the appropriate planting density and time of lupine intercropping for harnessing the possible maximum productivity of barley fields. Factorial combinations offour time of lupine intercropping (on the same date, two weeks, four weeks and six weeks after barley sown) and three planting densities of lupine (5cm, 1 Ocm, l 5cm intra-row spacing between lupine plants) as well as two sole cropping of barley and lupine were laid out in randomized compete block design (RCBD) with three replications. The results indicated that there was no significant difference among all treatment combinations on phenological, vegetative growth and yield related parameters of barley. Except days to 50% emergence and number of grain per pod. However, highly significant differences among treatment combinations were observed for all growth and yield parameters of lupine. In the intercropping system of lupine with barley, the base crop barley completely dominated lupine in all treatment combinations. The land equivalent ratio (LER) was more than one in most cases to show more advantages of intercropping of lupine with barley than their sole cropping separately. The highest LER (1.48) and monitory advantage index (MAI) (17011.8) were recorded in the intercropping of lupine simultaneously with barley at low planting density which was intercropped with l 5cm intra-row spacing between lupine crop. The economic analysis had also confirmed that this treatment combinations (lupine intercropping simultaneously with barley at low planting density) gave the best advantage in the study area that can be recommended for further adoption by barley producing farmers. But, to come up with pragmatic recommendations for wider utilization of intercropping of lupine with barley, similar studies should be carried out further in different areas and cropping seasons.