A nested finned heat sink with heat pipe(s). A heat dissipation unit includes a base seat and a first radiating fin assembly. The first radiating fin assembly includes multiple first radiating fins. Two ends of each first radiating fin are respectively formed with a first end edge and a second end edge on a first side. The respective first radiating fins are nested with height and width gradually increased. Each first radiating fin is formed with at least one first support section and a first opening in a position corresponding to the first support section. The first support section abuts against and supports another first radiating fin.