The results of a molecular orbital study on structures and stabilities are presented for the hydrated clusters of the hydrogen fluoride (HF) molecule, HF(H2O)(n) (n = 1-7). For each cluster system, the most stable structure is found to be the non-proton-transferred type, but not the ion-pair form. The computational results are quite consistent with the weak acidity of the HF in water. The differences between HF(H2O)(n) and HCl(H2O)(n) cluster systems are further discussed for the structure and stability depending on the cluster size. The calculated IR spectra of the stable HF(H2O)(n) clusters predict large red-shifts of H-F and hydrogen-bonded O-H stretching frequencies.