We have conducted an eight station, very long baseline interferometric (VLBI) experiment to produce spectral-line synthesis maps of the hydroxyl (OH) maser emission from regions of active star formation (i.e., interstellar OH masers). In this paper we report on the observations of W3(OH) for which data from 13 baselines were correlated and calibrated. The observations are well distributed over the (u,v)-plane, allowing the source brightness distribution to be recovered by Fourier inversion of the interferometric data. In this manner the maser emission from the 1665 MHz OH transition toward W3(OH) has been mapped with a synthesized beam of 0''.01 and with a spectral resolution of 0.14 km s/sup -1/. This map is complete in the velocity range of -50 to -41 km s/sup -1/ to a limiting sensitivity of 5 Jy.