The study was designed to analyze some of the Green HR practices and their influence on environmental sustainability. The main variable for the study was to establish the influence of Green Human Resource management practices on environmental sustainability at Menengai Oil Refinery in Nakuru; Kenya. The study adopted a descriptive design, specifically a case study at Menengai Oil Refinery. Primary method of data collection was applied where questionnaires were used. The study targeted 275 permanent employees, from which a sample size of 163 employees was selected. Questionnaires were used in the data collection. The data was then analyzed using descriptive and inferential statistics and presented inform of tables. The findings included: Green employee sourcing had a weak insignificant influence on environmental sustainability, Green occupation health and safety had a significant influence on environmental sustainability, Green training and development programs did not influence much environmental sustainability, Green performance management had significant influence on environmental sustainability and finally the influence of NEMA policies and regulations had the greatest influence on environmental sustainability. The study thus recommended that Menengai Oil refinery should strengthen its green performance management and occupational health systems to ensure environmental sustainability.