Data of nighttime image quality measurements carried out during the period from August 1996 to December 2003 at Maidanak observatory in Uzbekistan are presented. Nighttime image quality was measured with an ESO Differential Image Motion Monitor (DIMM). The median and mean values of FWHM, the full width at half maximum of a long-exposure stellar image at zenith at λ = 550 nm, for the entire period of observations made 0.71''and 0.77'', respectively. The best image quality is observed in Maidanak in October and November. Weak correlation has been revealed between the image quality and near-ground wind speed.