In Tunisia, crop spraying is conducted under poorly controlled conditions. Important pesticide a;ounts are transferred in environnement, with negative impacts in ecosystem, health and economy. An original method has developed to assess spray losses during cereal pesticide application, under field and laboratory conditions in Tunisian context. Some natural and artificial collectors were used to trap the droplets containing a fluorescent tracer dye (Brilliant SulfoFlavine: BSF). Four test series were carried out, in wind tunnel and field conditionsm under two configurations, to assess spray drift and deposits under the sprayer boom, using a classic flat fan nozzle. The average captured on the ground was 30% to 65% of the sprayed tracer dose and 3% to 15.5% on plants. In the atmosphere, it varied between 8% and 16% of this same volume.