We present first results from our search for brown dwarf and giant planet companions around G and K type stars in the Upper Sco OB association. Our survey is designed to detect companions as faint as I=20 about 2 arcsec from the star. This sensitivity corresponds to 10MJ at 300 AU according to current evolutionary models. The host stars were selected from Prebisch et al. (2001) using proper motions. The substellar candidates were selected using Optical/Near Infrared colors derived from images that were obtained using 1.5m Carlos S&#225nchez Telescope and the IAC-80 Telescope, both located in Teide Observatory (Canary Islands). From a sample of 65 stars we have obtained 80 candidate companions.We have obtained optical spectra for 8 of these objects using WHT-ISIS and CTIO 4m -RCSpec. We have found no confirmed substellar companions in those candidates, which represents only 10% of our complete list. We plan to apply for spectroscopic follow-up for the remaining 90% of the candidates.