We present the results of adaptive-optics imaging in the H and K bands of 12 low and intermediate redshift (z < 0.6) quasars using the PUEO system mounted on the Canada-France-Hawaii telescope. Five quasars are radio-quiet and seven are radio-loud. The images, obtained under poor seeing conditions, and with the QSOs (m_V > 15.0) themselves as reference for the correction, have typical spatial resolution of FWHM ~ 0.3 arcsec before deconvolution. The deconvolved H-band image of PG 1700+514 has a spatial resolution of 0.16 arcsec and reveals a wealth of details on the companion and the host-galaxy. Four out of the twelve quasars have close companions and obvious signs of interactions. The two-dimensional images of three of the host-galaxies unambiguously reveal bars and spiral arms. The morphology of the other objects are difficult to determine from one dimensional surface brightness profile and deeper images are needed. Analysis of mock data shows that elliptical galaxies are always recognized as such, whereas disk hosts can be missed for small disk scale lengths and large QSO contributions. Based on data obtained at the Canada-France-Hawaii telescope which is operated by CNRS of France, NRC of Canada and the University of Hawaii.