Niobium pentoxide (Nb2O5) nanoparticles were synthesized by laser ablation in water employing 1064nm, 12.09 J/cm2 laser fluence and 150 pulses. X-ray pattern showed intense peaks of orthorhombic T-Nb2O5 and the grain sizes ranged from (58.245 -244.664nm) while dislocation density was (0.294—0.016nm) and micro strains were (5.2-3.4nm). The optical properties showed an absorption edge at (309nm) and the energy band gap was (4.15eV). TEM image showed spherical agglomerated particles with moderate concentration, while the average particles size was about (40nm). FESEM images also showed small spherical particles aggregated forming larger sized particles and the average particles size was less than (30nm). EDX image confirmed the existence of niobium and oxygen elements and the stoichiometry of niobium pentoxide was 66.03%. AFM image showed vertically oriented (pyramid shaped) particles with average particle size (9nm) while roughness was (3.558nm) and RMS roughness was (4.194nm). FTIR results and Raman spectroscopy showed a peak referring to the Nb-O-Nb bond which indicates the formation of the Nb2O5 complex