A field experiment was conducted at the Farm of Medicinal and Aromatic plants Section, Dokki during two seasons 1995 and 1996 to study the effect of different planting distances (40, 50, and 60 cm) on the number of flowers, fresh and dry weights as well as their content in different picks and also in different stages of flower buds development. The results showed that, the number of flowers, fresh and dry weights per plant significantly increased by increasing the distance be‌tween plants. Also the fresh and dry weights per plot significantly in‌creased by increasing distances between plants up to 50cm. The data also showed that during the growing season, seven picks were taken from the plants, and the number of flowers, fresh and dry weights per plant and per plot increased steadily up to fourth and fifth pick, and then they decreased. The data however showed an opposite effect of planting distances on the fresh and dry weights per plot i.e. the distance 50 cm gave the highest weights. As for pyrethrin content and its yield the data showed generally that the planting distance 50 cm gave the highest content and yield of pyrethrin I . The data showed that there were seven stages of flower bud development and that the pyrethrin I content increased gradually until it reached the seventh stage, which is the best stage for picking the flower. Therefore, it could be recommended to plant pyrethrum plant at 50 cm distances and to pick the flower at the seventh stage, i.e. the flower is well developed and full expanded and the white ray flowers are horizontal and parallel to the surface of the soil. This is the best stage for picking the flowers.