The disclosure is directed to a fuel-air mixing device for an internal combustion engine. The fuel-air mixing includes an inner elongated hollow body portion for delivering a fuel-air mixture from a carburetor or a fuel-injection device into the inlet of the intake manifold of the engine. The device includes an outer elongated body portion within which the inner body portion is disposed. The cavity is formed between the interior surface of the outer body portion and the exterior surface of the inner body portion. The cavity is open at one end portion facing the flow of the fuel-air mixture. The opposite end of the cavity is closed. The fuel-air mixture contains droplets of fuel which pass adjacent the inner surface of the carburetor or the fuel injection device. Such droplets enter the opening of the cavity of the mixing device and accumulate therein. Additional in the mixing device enable a small portion of the flow of the fuel-air mixture to move inwardly therethrough and into the cavity. As a result, the small portion of flow causes the liquid fuel within cavity to pass through the opening of the cavity, into the inner body of the mixing device, and into the main flow of the fuel-air mixture passing through inner body portion. Thereby, the liquid fuel droplets accumulated in the cavity are vaporized within the flow of fuel-air mixture entering the inlet of the engine.