The effect of soil CO2 on the development of vegetable crops is not well-understood. An inexpensive and simple method for monitoring soil CO2 levels is needed to study those effects. A soil gas extraction apparatus was constructed from polyvinyl chloride (PVC) pipe, tygon tubing, and Plexiglas. The apparatus was placed into soil covered with black plastic or spray-on mulch or left bare. Gas samples were collected twice weekly after canopy closure of eggplant (Solanum melongena L., cv Black Bell) and continued through the last harvest. A vacuum pump was used to pull gas samples from 16 inches (41 cm) below the soil surface for collection in an airtight foil bag. The CO2 levels, recorded over time and between treatments, was determined with detector tubes available commercially and compared to gas chromatography results. Detector tube CO2 levels were comparable to the samples from the same bags measured by gas chromatography. This system was able to monitor differences in soil CO2 levels between treatments and over time.