Various activities taking place in urban areas lead to the emission of a number of polluting substances that have adverse effects on the environment and ecosystems and contribute to the deterioration of the quality of the air, the soil and water. The plants grown there suffer damage due to pollution, which has the effect of negatively affecting their morphological, physiological and biochemical properties. This study was conducted to evaluate the pollution of some lettuces crop sites in the city of Daloa (Côte d’Ivoire) by measuring anatomical and biochemical parameters of lettuce (Lactuca sativa). These include stomatal density and opening, relative water content, pH, ascorbic acid content, chlorophyll, and carotenoid. These parameters made it possible to calculate the lettuce Air Pollution Tolerance Index (APTI). The results showed a reduction in stomatal density and opening, as well as pH, ascorbic acid and chlorophyll content for sites 1 and 2 in downtown of Daloa compared to site 3 located, farther away from the city center. Site 1 has an average carotenoid content (31.23 mg/g) of lettuce significantly lower than that of sites 2 and 3 which is respectively 59.70 mg/g and 58.97 mg/g. Also, significant reductions of 8.25% and 9.5% in the relative water content of lettuce at site 3 compared to sites 1 and 2 were observed. The calculation of APTI revealed the relative sensitivity of lettuce in sites 1 and 2 to pollution, compared to site 3. This study shows that sites 1 and 2 have a high risk of pollution, compared to site 3 with regard to the different parameters evaluated.