In Nova Scotia, a shift has occurred focusing on constructed wetland systems as an effective treatment option for agricultural wastewater.� Although much research has examined the water quality treatment aspects of these systems, there has been limited interest in examining the air quality effects.� As such, the objectives of this study were to examine the changes between growing season (GS) and non-growing season (NGS) greenhouse gas emissions from these living treatment systems.� Six pilot-scale (6.6 m²) constructed treatment wetlands were established at the Nova Scotia Agricultural College's Bio-Environmental Engineering Centre in Truro, Nova Scotia, Canada.� The wetlands were constructed to allow for continuous wastewater loading at two rates: typical (70 L d^-1) and high (140 L d^-1) and contained either aquatic vegetation (cattails) or no vegetation.� Each wetland had a removable chamber to allow for continuous measurements of CO₂, CH₄, and N₂O emissions using a mass balance approach.� During the GS, average CO₂ uptakes were large (approximately -40 g CO₂ m^-2 d^-1) for the wetlands with dense vegetation (approximately 100% cover) at the typical loading rate.� For those wetlands at higher loading rates, CO₂ emissions were observed to be as high as +11 g CO₂ m^-2 d^-1.� Methane emissions from the wetlands were closely related to the presence of plants and wastewater strength.� Wetlands with typical wastewater loading rates and an abundance of aquatic vegetation produced average CH₄ fluxes of approximately 35 mg m^-2 d^-1, while higher wastewater strength systems with little vegetation approached 85 mg m^-2 d^-1.� During the NGS, all vegetated wetlands exhibited higher CH₄ emissions than the non vegetated systems.� Nitrous oxide emissions were generally negligible for all the wetlands, regardless of time of year.�