Sisal supported 2, 4-dichloro-1, 3, 5-triazine (Sisal-DCT) was found to be an environmentally renewable, inexpensive solid acid catalyst for the electrophilic substitution reaction of indole with carbonyl compounds to the corresponding bis(indolyl)methanes in excellent yields. The important features of the procedure are cost effectiveness, faster reaction rates and cleaner conversions with simple work-up.