The structures of small water clusters (up to 8 molecules) have been studied using gradient-corrected density functional theory and ab initio molecular dynamics. For smaller clusters (3, 4 and 6 molecules) ring structures were found to be the most stable, while for octamers three-dimensional structures are lower in energy. All our results are in good agreement with existing HF-based calculations. We have also calculated the hydrogen stretching frequencies for the dimer and trimer.