The objective of the study was to determine differences in welfare levels between heritage breed hens (Yellowleg Partridge, Sussex, Leghorn) and commercial crosses (ISA Brown, Lohmann Brown, Hy-Line) kept in the litter system with no outdoor access. The experiment was carried out with 180 hens of three heritage breeds (Yellowleg Partridge, Sussex, Leghorn) and 180 commercial crosses of laying hens (Hy-Line, ISA Brown, Lohmann). Layers were reared in the litter system with no outdoor access. During the experiment, production data were collected until 38 days of age and birds' behaviour was monitored for 24 h at 18, 20, 32 and 38 weeks of age. O f the three commercial lines of laying hens kept in the litter system with no outdoor access, the lowest welfare levels were characteristic of ISA Brown birds. Hy-Line and Lohmann layers were characterized by comparable welfare levels that were higher in relation to ISA Brown layers. The results also showed that Sussex hens reared in the litter system had higher welfare levels than Yellowleg Partridge and Leghorn hens. When comparing the results of heritage breed and commercial hens, it can be said that mortality and increased levels of aggression in heritage breed hens kept in the litter system suggest that their welfare levels were lower than in commercial layers.