We present here an analysis of several possible reactive pathways toward the formation of hydroxylamine under astrochemical conditions. The analysis is based on ab initio quantum chemistry calculations. Twenty-one bimolecular ion–molecule reactions have been studied and their thermodynamics presented. Only one of these reactions is a viable direct route to hydroxylamine. We conclude that the contribution of gas-phase chemistry to hydroxylamine formation is probably negligible when compared to its formation via surface grain chemistry. However, we have found several plausible gas-phase reactions whose outcome is the hydroxylamine cation.