Sacred Groves are ecologically significant forest patches preserved through traditional beliefs and community-based conservation practices. They contribute to environmental sustainability by sequestering carbon, conserving native biodiversity, preventing soil erosion, enriching soil fertility, regulating hydrological cycles, supporting natural regeneration, and maintaining ecological connectivity. Therefore, the current study investigates the variation in tree biomass components and regeneration attributes across twelve Sacred Groves in Himachal Pradesh, India, within the north–western Himalayan region. The primary objective was to assess their contribution to conserving biomass accumulation potential and regeneration status with adjacent forests impacted by anthropogenic pressures. Twelve sites (S1–S12) were selected across elevations ranging from 1400 m to 3000 m, categorized into Sacred Groves and Adjoining Forests. This study found consistently higher biomass in Sacred Groves, with total biomass ranging from 280.09 to 1530.21 t ha⁻¹ (mean 885.84 t ha⁻¹), compared to 341.56 to 967.96 t ha⁻¹ (mean 593.20 t ha⁻¹) in adjoining forests. Sacred Groves also exhibited superior natural regeneration, with recruit densities ranging from 750 to 7,500 ha⁻¹, establishment rates from 25.49% to 183.72%, and regeneration success between 60% and 275%. These results underscore the ecological maturity, stability, and resilience of Sacred Groves, emphasizing their critical role in maintaining biodiversity, enhancing carbon storage, and providing essential ecosystem services. As such, Sacred Groves are vital for supporting long-term ecological health and mitigating the impacts of increasing anthropogenic pressures and climate change. Their preservation is crucial for sustaining the ecological balance in the region.