This new edition of the code has been prepared by the Commission for Research Integrity and approved by the General Assemby of the Polish Academy of Sciences in June 2020. Good research practices are presented in the context of data management; research environment; training, supervision and mentorship; research procedures; safeguards; collaborative working; publication; reviewing and evaluation; conflict of interest (CoI). It is now recommended that each scientist file an annual declaration of CoI while the possible need for its addressing will be determined by the leaders of academic/scientific institutions. Violations of research integrity are briefly presented as well as dealing with those violations as well as with allegations of misconduct.