Background: Pulmonary function testing is a routine procedure for the assessment and monitoring of respiratory diseases. Aim: To estimate the values of peak expiratory flow rate (PEFR), forced expiratory volume in first second (FEV1), forced vital capacity (FVC) and ratio between FEV1/FVC among smoking and nonsmoking students, staff and workers at Al-Zarqa Private University and to study the effect of age, gender and body mass index (BMI) on these variables. Subjects and methods: A cross-sectional research design was used. The study was conducted at Al-Zarqa Private University, Jordan. Two hundred and thirteen healthy smokers and nonsmokers were approached through probability sampling among the students, staff and workers of Al-Zarqa Private University were screened through a questionnaire and spirometric test. Data from 213 subjects was used for analysis. Subjects were excluded if pregnant, or with cardiopulmonary disease body, mass index (BMI) not ranging from 17-25, FEV1/FVC% less than 70 or with no reproducible results. Results: Mean FVC, FEV1 FEV1/FVC% and PEFR were found to be lower in smokers than the nonsmokers, there were significant differences between mean spirometric values smoking and nonsmoking in age 20-30 years and 30-39and 40-49. Conclusion: The mean FVC, FEV1 and PEFR were lower in smoker. In order to generalize these reference values, a larger study following the ATS criteria is needed. Health education campaign needed to keep community aware of the risk of smoking.