This open science checklist is for researchers, trainees and students to assist them in implementing open science in their research activities. The checklist is inspired by open science principles, the Netherlands Code of Conduct for Research Integrity, the REWARD movement and the replicability crisis. It consists of 14 items divided over individual phases of the research process, except items four and five that are more generally applicable. Per item we refer to the corresponding chapter in our Open Science Research Manual and to the corresponding REWARD pillar or article(s) in the Netherlands Code of Conduct for Research Integrity. Some items focus more on quality aspects because sharing materials is most valuable if it is of high quality. Items concerning privacy and research ethics provide the boundary conditions for open science.