Offering market-linked long-term solutions, ecotourism the newly establishing industry not only provides effective economic incentives for conserving and enhancing socio-cultural diversity but also helping to protect the natural and traditional heritage in an area. So, a study was aimed to assess the existing ecotourism sites operating in Himachal Pradesh, India for sustainability using UNWTO indicators. Amongst the PPP sites Aamod, Shoghi with a mean rank of 53.33 was found to be the least sustainable, followed by Nature Camp, Narkanda (40.56) > Park woods, Aanji (28.89) > Aamod, Dalhousie (36.17) > Nature Camp, Sanawar (34.39) > Nature's Treat Khalogra, (33.89) > Himalayan Nature Camp, Jalodi (28.78). While Pine Hills Eco-Camp, Chewa with a mean rank of 26.83 was found to be the most sustainable PPP site. However, amongst the Departmental sites, Ecotourism Site, Paneo (50.28) was found to be least sustainable followed by Ecotourism Site, Sahoo (42.11) > Nature Park, Jhiri (38.17) > Ecotourism Site, Holi (36.83) > Children's Park, Hamirpur (34.44) > Ecotourism Site, Devidarh (33.11) > Ecotourism Site, Kasol (30.39). Ecotourism Site, Prashar (26.67) was found to be the most sustainable. Overall, PPP sites with a mean rank of 8.11 were found to be more sustainable than the Department ecotourism sites with a mean rank of 10.89. Analyzing the impact of ecotourism activity on the selected indicators it was also found that the most impacted indicator is potable water demand with a total indicator score of 28 at PPP sites followed by energy consumption = waste management = cost to users indicators (24) > community involvement (23) > tourists facilitation (20) > bio-capacity (18) > building material (16) > local employment indicator (15). Correspondingly, energy consumption and waste management indicator were found to be highly impacted by Departmental activities with a total indicator score of 30 each, followed by community involvement (26) > building material (25) = tourist facilitation (25) > local employment (22) > potable water demand (20) > cost to users (18) > bio-capacity (17).