Four polyimides containing hexylene spacer and a fluorostilbene unit in the side chains were prepared in thin-film form by two-step condensation of 3,3'-bis[(4'-fluoro-4-stilbenyl)oxyhexyloxy]-4,4'-biphenyldiamine (FS6B) with pyromellitic dianhydride (PMDA), benzophenone-3,3',4,4'-tetracarboxylic dianydride (BTDA), 4,4'-oxydi(phthalic anhydride) (ODPA), and 4,4'-hexafluoroisopropylidenedi(phthalic anhydride) (6FDA), respectively, and their controllability of liquid crystal (LC) alignment on rubbed surfaces was investigated. Pretilt angles of LCs were achieved in the 2-9 degrees range, depending on the rubbing density and backbone structures. The effect of the mesogenic stilbene group on the pretilting of LCs was distinctive in FS6B-PMDA. Contact-angle measurements on thin films annealed at 120 degreesC revealed that FS6B-PMDA potentially had the better alignment stability than FS6B-6FDA.