A comparative study on natural rubber (NR) biodegradation through solid-state fermentation (SSF) and submerged fermentation (SmF) has been carried out for both bacterial as well as fungal species. Changes in the organic carbon content along with the average molecular weight of the treated rubber samples indicated rubber hydrocarbon utilization and its degradation. Proportion of sol and gel content of the treated rubber also varied with the SmF and SSF treatment. Further, presence of aldehyde groups in the treated rubber indicated rubber biodegradation. The comparative results showed SSF to be a better treatment method for rubber biodegradation. (C) 2005 Elsevier Ltd. All rights reserved.