Viewed from the side, the bridge of the muzzle forms a right angle to the line of the forehead. Lips are tight and clean. The Chihuahua has a complete set of evenly spaced, white teeth meeting in a scissors or level bite. Nose color varies with coat color. Eyes are large and full but not protruding, and set well apart.
Expression is bright and the eyes are luminous.
Ears are large, erect, and set so that the bottom edge of the ear is attached at the same level as the outer corner of the eye. The ears are normally carried so that the tips point slightly outward. A line drawn from the outer corner of the eye to the inner corner and a line drawn from the inner corner of the eye to the tip of the ear form a 45-degree angle. When the dog is alert, the ears may be raised slightly. Longhaired Chihuahuas whose ears droop slightly as a result of the weight of heavy fringing on the ears are not to be penalized.