2′-Fluoro-nucleoside compounds are disclosed which are useful in the treatment of hepatitis B infection, hepatitis C infection, HIV and abnormal cellular proliferation, including tumors and cancer. The compounds have the general formulae: wherein Base is a purine or pyrimidine base; R1 is OH, H, OR3, N3, CN, halogen, CF3, lower alkyl, amino, loweralkylamino, di(lower)alkylamino, or alkoxy; R2 is H, phosphate, or a stabilized phosphate prodrug; acyl, or other pharmaceutically acceptable leaving benzyl, a lipid, an amino acid, peptide, or cholesterol; and R3 is acyl, alkyl, phosphate, or other pharmaceutically acceptable leaving group; or a pharmaceutically acceptable salt thereof.