We present cosmological results from the statistics of lensed quasars inthe Sloan Digital Sky Survey (SDSS) Quasar Lens Search. By taking properaccount of the selection function, we compute the expected number ofquasars lensed by early-type galaxies and their image separationdistribution assuming a flat universe, which is then compared with sevenlenses found in the SDSS Data Release 3 to derive constraints on darkenergy under strictly controlled criteria. For a cosmological constantmodel (w = -1) we obtain ΩΛ =0.74+0.11-0.15(stat.)+0.13-0.06(syst.). Allowing w to be a free parameter we findΩM = 0.26+0.07-0.06(stat.)+0.03-0.05(syst.) and w =-1.1 ± 0.6(stat.)+0.3-0.5(syst.) whencombined with the constraint from the measurement of baryon acousticoscillations in the SDSS luminous red galaxy sample. Our results are ingood agreement with earlier lensing constraints obtained using radiolenses, and provide additional confirmation of the presence of darkenergy consistent with a cosmological constant, derived independently oftype Ia supernovae.