Various studies have indicated that petrol and its vapours affect proper functioning of many organs, and some of the constituents of petrol are considered to be carcinogen. Incidence of lungs, kidneys, liver, pharyngeal, and laryngeal cancers were in higher petrol pump workers as compare to the normal population[1,2]. Studies have shown that petrol pump workers have lower value of Force vital capacity (FVC) and force expiratory volume in first second (FEV1) as compare to the control group [3,4]. Hence, the present study aims to confirm the decline in the respiratory functions in petrol pump workers (filling attendants) who are continuously exposed to petrol/diesel vapours during duty hours. Petrol pump workers in Karachi, Pakistan are working on a 24 hours shift, which is a considerable amount of time of exposure to petrol and its vapours. A comparative cross sectional study was conducted on 60 males working at petrol pump served as study group, while 40 age match healthy individuals were chosen to be control group. Petrol Stations were visited by the research team and after meeting with the manager; consent was taken from him and the subjects (petrol pump workers) who were involved in this study. Subjects were asked about demographic data, and after that were asked to perform the spirometry on vitalograph three times after the explanation about the procedure. The best value out of those was recorded for the analysis. Height and Weight were also measured along with the pulmonary functions. The two groups were compared by using ‘independent – t’ test and p value of less than 0.01 was considered significant. The mean FVC and FEV1 values of the study group was 3.15 ± 0.45 and 2.85 ± 0.56 compared to control group’s which was 3.92 ± 0.62 and 3.27 ± 0.63 respectively. While the FEV1/FVC ration were within the normal range in both of these groups. These results showed that both FVC and FEV1 values were significantly lower i.e. P < 0.001 and P ≤ 0.001 respectively in petrol pump workers as compare to the control group. Due to the nature of the job, petrol pump workers are constantly exposed to petrol vapours and these findings shows that these petrol and diesel vapours are causing considerable damage to the pulmonary functions mainly on lower airways showing restrictive pattern of disease. Therefore efforts are required in this area both at the government as well as at the private level so that we can come up with a solution to negate these effects to ensure healthier environment. Hence cohort studies are needed to analyse these effects in further details.