High nitrogen containing mesoporous carbon nitride (MCN) was synthesized and investigated as a metal-free base catalyst for the Knoevenagel condensation of ethylcyanoacetate with aromatic aldehydes. The catalyst was found to be efficient for the Knoevenagel condensation performed under microwave irradiation. The yields obtained were in the range 75-95% within short time of 12 min. The mesoporous carbon nitride was readily recovered and reused up to 5 cycles without losses in the catalytic activities. (C) 2011 Elsevier B. V. All rights reserved.