New DABCO-based chiral ionic liquids were synthesized and evaluated in asymmetric Diels–Alder reaction of cyclopentadiene with α,β-unsaturated aldehydes or 4-phenyl-3-buten-2-one. Chiral ionic liquid of modified MacMillan catalyst having a DABCO cation and hexafluorophosphate anion acts as organocatalyst (5 mol%) for the Diels–Alder reaction of crotonaldehyde and cyclopentadiene producing 98% of the product and 87% ee (endo) in CH3CN/H2O (95/5) at 25°C in 2 h. The scope and limitations of the catalysis were also studied by using cyclopentadiene and α,β-unsaturated aldehydes, and the Diels–Alder products were obtained in 18%–92% yields with 68%–93% ee. The catalyst was recycled and reused up to 6 cycles with a slight drop in ee and conversion of the product.