The objective is to determine the relationship between the attitude and the practice of preventive measures on COVID-19 in workers aged 18 to 70 years of both sexes at the Oscar Iván Market in Iquitos 2021. The study was Quantitative with a non-experimental, correlational and cross-sectional design, the population was made up of 128 workers from the Oscar Iván Market in the city of Iquitos. The techniques used were the interview and observation, the instruments were the Attitudes Scale towards COVID-19 (Validity 93.0% and Reliability 90.7%), and the COVID-19 preventive measures observation guide (Validity 94.4% and Reliability 92.6%). It was found 78.9% workers had a negative attitude towards COVID-19 while 21.1% had a positive attitude; In the practice of preventive measures against COVID-19, 76.6% had inadequate practice and 23.4% had adequate practice, when applying the Chi Square, ...