Environmental considerations are becoming an important factor in the choice of suitable remedial measures in addressing mitigation of landslides. This paper highlights the use of Nature-based Solutions (NbS) that are based on natural processes and ecosystems in the mitigation of eighteen unstable slopes along the Kandy-Mahiyangana Road in the Kandy district of Sri Lanka, which was implemented by the Road Development Authority and National Building Research Organisation. The sites were in the central fragile area of the country with high erosion susceptibility and reservoir siltation. The mitigation designs were hybrid-type with both structural engineering mitigations and NbS. NbS were chosen considering the critical habitat conditions, susceptibility to slope erosion, ecosystem functionality, adaptability to co-exist with the existing environment and other co-benefit functions of NbS. An array of on-site environmental management and bioengineering mitigation were used as NbS. This study portrays the application of NbS at every stage of the project cycle to ensure long-term disaster resilience and environmental sustainability.