The High Throughput X-ray Spectroscopy Mission XMM-Newton of the European Space Agency (ESA) was launched on December 10, 1999 by an Ariane V rocket. The satellite observatory uses three grazing incidence telescopes coupled to reflection grating spectrometers and x-ray CCD cameras. Each x-ray telescope consists of 58 Wolter I mirrors which are nested in a coaxial and cofocal configuration. The XMM-Newton Science Operation Center has completed a coherent program for the in- orbit calibration and performance verification of the x-ray observatory. This paper presents first measurement results of the x-ray telescopes image quality and effective area obtained during this campaign.