The oligosaccharide structures of glycoproteins can have a profound effect on properties critical to the development of glycoprotein products for human therapeutic or diagnostic use, including clearance rate, antigenicity, specific activity, solubility, resistance to thermal inactivation, and resistance to protease attack. Therefore, it is important to understand how bioprocess factors influence oligosaccharide structure. In this presentation, I will summarize literature data concerning potential effects of bioprocess factors on glycoprotein oligosaccharide biosynthesis. These data are drawn from two recent detailed reviews published by our laboratory describing the effect of cell culture conditions on N-linked glycosylation (10) and the effects of other bioprocess factors on both N-linked and O-linked glycosylation (11).