We report the discovery of a 14NH3 maser in the  (J,K)=(3,3)
transition  towards the W51-NORTH HII complex. The maser line
has a FWHM of 1.7 km/s and an asymmetric profile, suggesting multiple
features in the velocity range. Measured with the VLA,
the maser emission has a peak flux of 230 mJy and a maximum deconvolved
size of 0.2''. These values set a lower limit to the brightness temperature of 1.3x10^4 K (<A HREF="./paper/w51nh3maser.ps"> 	 Zhang & Ho 1995</A>)