A vibration isolating fuel pump assembly comprises a stationary support (14) to be mounted in a fuel tank. An inner retainer (16) is fitted in the stationary support (14). The inner retainer (16) has a retainer body (18) and at least two flexible legs (20) extending substantially vertically and connected to the periphery of the retainer body (18), the upper ends of the flexible legs (20) being firmly supported by the stationary support (14) in the upper part thereof. A fuel pump (12) is received in the retainer body. Each flexible leg has its lower end connected to the retainer body via a resilient connecting element having a generally S-shape profile.