Oil palm cultivation has drastically increased in the last decades and has become a key crop to meet the global vegetable oil demand, while raising environmental issues linked to deforestation, fertiliser or pesticide uses. Guidelines on best practices have been developed to limit these environmental impacts. However, there is little evidence on the field reality of concrete declination of these general guidelines and on the room for improvement of practices in light of the local diversity of oil palm systems. This study aimed to investigate in the field the actual practices in two contrasted areas in Indonesia, the first global palm oil producer. We carried out field surveys in Riau and Jambi provinces and collected data on annual applications of two synthetic mineral fertilisers, two herbicides and yields. We characterised the cropping systems of 88 smallholders' and 45 industrial plantation units including potential practice drivers. Both qualitative and quantitative analyses showed contrasted practices across growers. Fertiliser rates were variable across all grower types, while pesticide rates especially distinguished between industrial and smallholders' practices. Practices and performances were particularly variable amongst smallholders, and significantly different in Jambi compared to Riau. This study highlighted the great diversity of practices and potential environmental impacts. It stresses the need for a more systematic accounting of the local specificities of the cropping systems and their rationales in order to promote more adapted and efficient best practices recommendations.