We present images of the N 4 region in the Large Magellanic Cloud obtained with ISOCAM on board ISO through broad band filters centered at 6.75 and 15 μm. Far from the three H ii regions contained in the map, the emission at both wavelengths is due to the Unidentified Infrared Bands and associated continuum and originates in the external layers of a molecular cloud complex. The ratio between the intensities at 15 and 6.75 μm is ' 0.6–0.7 comparable to the 0.55–0.85 ratio found in our Galaxy. Closer to the H ii regions, this ratio increases when the ultraviolet radiation density reaches ' 10 times the radiation density near the Sun, due to the contribution of very small grains to the flux near 15 μm. The emission at both wavelengths is maximum in the direction of an interface between the main H ii region N 4A and the molecular cloud, a region very similar to the classical interface of M 17 in our Galaxy. We have detected at both mid-IR wavelengths the emission of a M supergiant present in the field.