Reestablishment of perennial vegetation is often needed after wildfires to limit exotic species and restore ecosystem services. However, there is growing body of evidence that questions if seeding after wildfires increases perennial vegetation and reduces exotic plants. The concern that seeding may not meet restoration goals is even more prevalent when native perennial vegetation is seeded after fire. We evaluated vegetation cover and density responses to broadcast seeding native perennial grasses and mountain big sagebrush (Artemisia tridentata Nutt. spp. vaseyana (Rydb.) Beetle) after wildfires in the western USA in six juniper (Juniperus occidentalis ssp. occidentalis Hook)‐dominated mountain big sagebrush communities for three years post‐fire. Seeding native perennial species compared to not seeding increased perennial grass and sagebrush cover and density. Perennial grass cover was 4.3 times greater in seeded compared to non‐seeded areas. Sagebrush cover averaged 24% and < 0.1% in seeded and non‐seeded areas at the conclusion of the study, respectively. Seeding perennial species reduced exotic annual grass and annual forb cover and density. Exotic annual grass cover was 8.6 times greater in non‐seeded compared to seeded areas three years post‐fire. Exotic annual grass cover increased over time in non‐seeded areas, but decreased in seeded areas by the third year post‐fire. Seeded areas were perennial‐dominated and non‐seeded areas were annual‐dominated at the end of the study. Establishing perennial vegetation may be critical after wildfires in juniper‐dominated sagebrush steppe to prevent the development of annual‐dominated communities. Post‐wildfire seeding increased perennial vegetation and reduced exotic plants and justifies its use.