Intrathecal drug administration is an important component of the management of malignancy and symptom control. This route of administration reduces systemic adverse effects, but can increase the risk of local adverse effects such as arachnoiditis. It is accepted practice that any spinal injection should not contain any preservatives (such as benzyl alcohol and parabens-containing compounds). The intrathecal administration of solutions preserved with benzyl alcohol has been shown in case studies to increase the risk of adverse neurological events. Available data do not support the safety of intrathecal injection of products preserved with parabens; rather, they demonstrate a need for further investigation. Steps should be taken to ensure that preservative-free products are used. Staff involved with the preparation and administration of intrathecal preparations need to be educated about the risks associated with preservatives in this setting.