Disclosed herein are an apparatus and method for measuring quality of an image received via a communication network. The apparatus includes an interface unit, a codec unit, a test image detection unit, and a Mean Opinion Score (MOS) measurement unit. The interface unit receives an image, including a start synchronization image and a test image via a communication network. The codec unit decodes the received image into a color signal. The test image detection unit detects any one value of brightness, saturation and hue information of the color signal input from the codec unit, calculates an average value for each frame, and detects the test image from the received image based on the calculated average value. The MOS measurement unit synchronizes the test image with a corresponding reference image, compares the quality of the test image with the quality of the reference image, calculates an MOS value based on the results of the comparison, and outputs the MOS value.