The influence of tobacco leaf maturity at the moment of harvesting on yield and quality was investigated in North Croatia through the period from 1983 to 1986. Over the first two years, experiments were made with the Drava cultivar, while over the following two years the cultivar McNair 944 was also included in the experiments. The tobacco was fertilized with 21 and 42 kg/ha of nitrogen added in the fertilizer mixture NPK 7:14:21. The tobacco was harvested in the stage of visually estimated technological maturity, and one or two harvests earlier (immature and very immature tobacco) and one harvest after visually estimated technological maturity (overmature tobacco). Three leaves were picked in each harvest. Depending on the year and the position of the leaf on the stalk, the time period between harvests varied from 6 to 28 days. During the first two years, the experiment was set up according to split-plot method and during the second two years it was set up according to the split-split-plot method. The experiment results indicate that maximum yields and best quality tobacco of the Drava cultivar were obtained by harvesting in the stage of maturity or overmaturity. In the case of the McNair 944 cultivar, the maximum values for both these properties were obtained by harvesting in the proper maturity stage. The maximum nicotine content was obtained by harvesting in the phase of immaturity and proper maturity of the tobacco. The content of reducing sugars have been obtained by harvesting overmature tobacco.