Deconvolution from wavefront sensing is a new technique of high-resolution imaging through atmospheric turbulence developed at ONERA. The capabilities of the method have been demonstrated during first laboratory experiments. A deconvolution experimental set-up was installed on the 4.2 m William Herschel telescope on La Palma in November 1990. The results obtained during these observations are presented: the astronomical sources were observed at optical wavelengths; the resolution improvement reached a factor greater than 10.