To assess the effect of potassium fertilization rates at [0.0, 50, 75 and 100 kg/fed. as potassium sulphate (48 % K₂O)], different nano-chitosan concentration (0.0, 2.5 and 5 ml/l) and their combination treatments on growth and productivity of chamomile (Matricaria chamomilla, L.), field experiment was conducted in private farm in Mansoura District, Dakahlia Governorate, Egypt, during the two winter consecutive seasons of 2016/2017 and 2017/2018. Treat chamomile plants with potassium fertilizer or/and nano chitosan induced significant increases in vegetative growth (plant height, number of branches/plant, fresh and dry weights of herb/plant), yield components (dry flower heads yield/plant and /feddan, yearly), volatile oil production (volatile oil percentage, volatile oil yield/plant and /feddan, yearly) and chemical constituents (K and total carbohydrates percentages in flower heads and total chlorophyll a + b content in leaves), as compared with control plants which untreated with potassium fertilization and nano-chitosan. . Generally, the obtained results indicated that growth and productivity of chamomile plants could be enhanced by the addition of potassium at 100 kg potassium sulphate  /feddan in combination with the foliar application of 5 ml/l nano-chitosan grown in clay loamy soil under Dakahlia Governorate conditions.