In a turfgrass system under continuous traffic stress, overseeding is a common practice to improve turfgrass cover in worn out areas. Athletic field managers often use three times the standard recomended rates for grass establishment. The purpose of this research was to determine the optimum rates and schedules to overseed in a system under continuous traffic stress. This study was conducted at the Horticulture Research Farm in Ames Iowa. The species evaluated were Perennial ryegrass (Lolium perenne L.)(PR) and Kentucky bluegrass (Poa pratensis L.) (KB). First trial started in 3 September, 2003 and finished on 28 June, 2004. An identical trial started on 1 September, 2004 and should conclude on 30 June, 2005. Football traffic simulation was applied weekly for 10 weeks after seeding with a GA-SWC traffic simulator. Seeding rates were 4.9, 9.8, 14.7, 19.5, 24.4, 29.3 and 34.2 g∙m^-2 for KB and 24.4, 48.9, 73.3, 97.7, 122.2, 146.6 and 171.0 g∙m^-2 for PR. Single seeding schedule (100% of seeds placed at the beginning of the trial) and multiple seeding schedule (20% of seed rate applied weekly over a 5 week period) were compared. By 14 November each year single seeding had significantly better percent ground cover in both species at all seeding rates than multiple seeding. Regression analysis on percent ground cover indicated that there is a significant positive effect of increased seed rates in both species and both seeding schedules at all evaluation dates. On 14 November 2003, ground cover ranged from 0.5 to 1.3% and from 1.3 to 3.3% on multiple and single seeding respectively for KB and from 22.5 to 65.0% and from 33.8 to 83.8% on multiple and single seeding respectively for PR.