For evaluating the response of growth and yield of lavender to ascorbic acid (0.0, 50, 100 and 150 ppm), nano-chitosan (0.0, 250, 500 and 750 ppm) and their interactions, an experiment was conducted at the experimental farm of Faculty of Agriculture, Zagazig University, Egypt, during the two consecutive summer seasons of 2018 and 2019. This experiment was arranged as split-plot experiment in the basis of completely randomized design with three replications. The main plots were occupied by four ascorbic acid (Asc) concentrations, also, the sub plots were entitled to four nano-chitosan (Nch) concentrations. Following data were recorded: plant height, number of branches per plant, dry weight of roots per plant as plant growth parameters as well as fresh and dry herb yield per plant and per faddan as yield components. However, 150 ppm ascorbic acid gave significantly higher values of growth and yield components compared to control and the other ones under study. Nano-chitosan at higher concentrations (500 and 750 ppm) significantly increased all the investigated parameters compared to control. The best results were achieved by the interaction treatment between ascorbic acid at 100 ppm + nano-chitosan at 750 ppm. This treatment could be used by the farmers under the same conditions because this it has the most profitable rate and concentration with the greatest yield advantages.