The objective of present investigation was the characterization of chitosan films after in vivo implantation. Chitosan films were prepared at three dose loadings of paclitaxel by classical casting method. They were implanted subcutaneously in Swiss mice in the neck region and were removed at 7, 15, 21 and 30 days post implantation for characterization. In vitro release studies on explanted films were done to observe the influence of the time of implantation and loading on paclitaxel release, which were correlated with amount of paclitaxel remaining in films. Residual amount of paclitaxel remaining in explanted films decreased with increase in loading i.e. after 30 days, the % residual content of drug at 25, 20 and 15 mg loadings (per film) were 13, 20 and 45% of the initial loading. The in vivo release of paclitaxel from films with higher loadings was higher, indicating that paclitaxel, per se, altered biodegradation of chitosan. Light microscopy and SEM studies of films removed from mice provided qualitative information on the loss of integrity and biodegradation of films with time. Further, FTIR and ATR-FTIR spectra revealed the changes in the film matrix that occur after implantation.