An investigation of a method to control pollutant emissions from a propane diffusion flame by modifying the air infusion rate into it is presented. The modification was achieved by installing a set of venturis around the burning gas jet (venturi-cascading). Propane jet diffusion flames at three burner-exit Reynolds numbers (Re=3600, 5100 and 6500) corresponding to burner-rim-attached in transition, and fully-lifted configurations were examined with several sets of venturis of different sizes and spacing arrangements. Temperature and concentrations of CO2, O-2, CO and NO in the exhaust products were measured with and without venturis (baseline case). The largest effect of the venturi-cascade was observed at Re=5100. The lowest emissions of NO and CO were achieved with a venturi throat diameter/burner-exit diameter ratio (D/d) equal to 32+/-3. The influence of the size of venturis was stronger than that of their spacing distribution. The flame structure measurements at those conditions showed that in the near-burner region of the venturi-cascaded flame the average values of temperature and CO2 concentration were lower by 5% and 7% respectively than those in the baseline flame. However, in the mid-flame and far-burner regions of the venturi-cascaded flame the average temperature was higher by 13% and 12%, and the average CO2 concentration was higher by 16% and 13%, respectively. In the near-burner, mid-flame, and far-burner regions, the venturi-cascaded flame had 16%, 5% and 3% lower average NO concentrations compared to the corresponding baseline flame. Laser Induced Fluorescence (LIF) measurements in the near-burner region of the venturi-cascaded flame indicated a decrease of 18%, 24% and 12% in the average concentrations of OH, CH and CN radicals, respectively, from their baseline values. However, in the mid-flame region, a 40% increase in OH from its baseline value was observed. In this region, CH and CN radicals were not detectable. The flow fields of the baseline and venturi-cascaded flames were numerically simulated using a computational fluid dynamics software package, and the role of venturis in enhancing the influx of air was confirmed.