From November 2008 to July 2010 we made 8300 drug tests to verify the absence of drug addiction or drugs/psychotropic substances consumption. We found 101 positive subjects (1.2%) at the first screening test; for fifty-five of them (54.5% of positives) we obtain a confirmation at second level test (0.7% of total tests). Sixty percent of these were positive for cannabinoids, 18.1% for opiates, 12.7% for cocaine, 9.0% for methadone, 3.6% for ecstasy and nobody for amphetamines. We noticed a good correlation between screening and confirmation tests for cannabinoids, methadone and cocaine. The analysis of the population of positive subjects shows that it's almost entirely composed by males, Italians, middle aged, heavy smokers and generally overweight, in apparent good health (average blood tests, any reported illnesses, any disability or any contraindications/limitations in employment).