Malignant gliomas are aggressive forms of primary brain tumors characterized by a poor prognosis. The most successful treatment so far is the local implantation of polymer carriers (Gliadel (R) wafers) for the sustained release of carmustine. To improve the effectiveness of local drug treatment, new polymer carriers and pharmacological agents are currently being investigated. Of particular interest is a set of novel thermo-gelling polymers for the controlled release of hydrophobic drugs such as paclitaxel (e. g., OncoGel (TM)). Herein, we use computational mass transport simulations to investigate the effectiveness of paclitaxel delivery from hydrogel-forming polymer carriers. We found similar (within 1-2 mm) therapeutic penetration distances of paclitaxel when released from these hydrogels as compared with carmustine released from Gliadel (R) wafers. Effective therapeutic concentrations were maintained for >30 days for paclitaxel when released from the hydrogel as compared with 4 days for carmustine released from Gliadel (R) wafers. Convection in brain tissue prevented the formation of a uniform drug concentration gradient around the implant. In addition, the surface area to volume ratio of the gel is an important factor that should be considered to maintain a controlled release of paclitaxel within the degradation lifetime of the polymer matrix. (C) 2011 American Institute of Chemical Engineers Biotechnol. Prog., 27: 1478-1487, 2011