Background: The development of industry in the field of transportation continues to increase. Increased number of motor vehicles followed by increased use of premium fuel and diesel fuel. Pollutants which are particularly present in vehicle exhaust gases. People in daily work are always associated with vehicle fumes such as motorcycle mechanics will get more vehicle emissions exposure than people who are not associated with vehicle fumes in their work. Incomplete smoke of the vehicle will produce harmful gases. Dangerous gases can enter the body through the respiratory tract. Most of the gases will accumulate in the bone marrow and soft tissue which will disrupt the process of hematopoiesis such as leukopoeiesis and may causes inflammation, and also allergic reaction of body. Many other jobs are at risk of exposure to low pollutants. This is makes researcher interested to examine whether there are differences in the differential counts of leucocytes in workers exposed to pollutants with workers not exposed to pollutants. Purpose: To know the difference of the differential counts of leucocytes in workers exposed to pollutants with workers not exposed to pollutants. Methods: The research methode used an analytic observational study with cross sectional design. This research is done by collected blood samples of workers unexposed to pollutan at Universitas Muhammadiyah Yogyakarta and workers exposed to pollutan at Bantul, Yogyakarta in the range of August in 2016 till May in 2017. Differential counts of leucocytes are examined from the blood sample in Balai Laboratorium Yogyakarta. Total samples is 40 samples consisted of 20 workers exposed to pollutan and 20 workers unexposed to pollutan. Data is analyzed with Independent Sample T-test and Mann Whitney Test. Results and Discussion: Average value of the basophile number in the pollutant exposed workers is 0.65% and the average basophile number in the unexposed pollutant workers is 0.45%. The average number of eosinophils in workers exposed to pollutants is 5, 20% and the average number of eosinophils on the workers is not exposed to pollutants is 4%. The average number of neutrophil segments in workers exposed to pollutants is 59.15% and the average number of neutrophil segments in workers not exposed to pollutants is 57.85%. Resulting in an average basophil, eosinophil, and neutrophil segment numbers in the exposed pollutant workers higher than unexposed pollutant workers. The average value of lymphocyte numbers in exposed workers pollutants is 29.90% and the average number of lymphocytes in workers not exposed to pollutants is 32.00%. The average monocyte rate in workers exposed to pollutants is 3.65% and the average number of monocyte numbers on workers is not exposed to pollutants is 4.25%. So that the average number of lymphocytes and monocytes in pollutant exposed workers is lower than that of unexposed pollutants. The average number of non segmented neutrophils in workers exposed to pollutants is 1.45%, and the average number of non segmented neutrophils in workers not exposed to pollutants is 1.45%, so the average number of non segmented neutrophils in workers pollutants exposure is equal to workers are not exposed to pollutants. There is no meaningful difference of differential counts of leucocyte between exposed pollutan workers and unexposed pollutan workers. It can be seen from the result of Independent Sample T-Test and Mann Whitney Test which showed p > 0,05 (p = 0,209 for basophil, p = 0,299 for eosinophil, p = 0,916 for non segmented neutrophils, p = 0,095 for monocyte, p = 0,586 for segmented neutrophils, p = 0,328 for lymphocyte).