Introduction: It is not yet established, in Algeria, a consensus on the use of prostate specific antigen (PSA) for the screening of prostate cancer (PCA) while some doctors speculate and recommend a serum-PSA assay to the young men. The objective is to assess the prevalence of PSA by age in young farmers. Methods: This study was undergone on 403 farmers, exposed to the risk of pesticides, aged between 30 - 70 years and living in rural areas of Saida (Western Algeria), during the period 2006 to 2012. The values of the PSA were collected during PCA screening and compared by statistical tests that revealed significant difference. Results: It was found that 15.6% of patients were under the age of 40 years. The total PSA (TPSA) increases with age and varies from 1 to 2 ng/ml for the respective age groups of 30 - 39 and 60 - 69 years. Approximately, 16.6% of men (or 1/6), who underwent PSA assay were under the age of 40 years. Conclusion: According to the recommendations of Algerian associations of cancer, men younger than 50 years may not be candidates for screening by PSA.