The present research was conducted to see the effect of stress on teaching effectiveness of secondary teachers of Agra city. ‘Stress’ was measured by Singh Personal Stress Source Inventory prepared by Arun Kr. Singh, Ashish Kr. Singh and Arpana Singh while Teaching Effectiveness Scale prepared by Umme Kulsum was used to measure the teaching effectiveness of secondary teachers. For this research a sample of 120 secondary teachers (60 male and 60 female) were selected. The sample was selected by stratified random sampling. Mean, SD and t-test were used to analyze the data. Very low negative correlation was obtained between variables stress and teaching effectiveness. It was concluded that stress effects the teaching effectiveness at some extent.