1 - This paper deals with several aspects related to the aplication of systemic insectisides on cotton. 2 - The I. A. Campinas 817 variety was used in the experiments carried on. Both laboratory and field and all the experiments were related in detail. 3 - The results obtained showed that utilization of systemic insectisides did not affect the seed germination capacity in tests made in germination apparatus. 4 - The field experiment results indicated that plants, as to blooming, bolls number, weigth, yeld and seed germination capacity as well as to fibers properties (lenght, lenght uniformity, strength, fineness, maturity) were not affected by the treatments. 5 - According with the data obtained we may conclued that the low percentage of seed germination in the field, as has been related by others must be due to factors not connected with the seeds treatments and that the systemics used did not affect the plant development.