A listening experiment was conducted to explore whether the perceived quality of an acoustic environment dominated by road traffic noise may be improved by adding pleasant water sounds. In a pilot study, 15 listeners assessed 14 water sounds on eight attribute scales. The results revealed a large variability in perceived pleasantness of water sounds. In the main experiment, 21 listeners assessed single and combined road-traffic and water sounds. The results indicated that when a pleasant water sound (sea waves) was added to the unpleasant road traffic noise it had a positive effect on the overall pleasantness of the combined sound, whereas an unpleasant water sound (waterfall) had a negative effect on the overall pleasantness of the combined sound. Adding water sounds to road traffic either increased or left unchanged but never decreased the eventfulness of the acoustic environment. Thus, the results suggest that adding a pleasant water sound may improve the overall pleasantness of a noisy acoustic environment. However, the perceived eventfulness of the acoustic environment may also increase, which may not be desirable if the goal is a calm acoustic environment.