A truck-mounted pickup arm assembly for collecting, lifting, and placing objects and trash and recycling materials in the truck includes three boom sections to facilitate articulation of the arm in complex configurations to extend to the front or side of the truck, to reach over obstacles, and to pick up articles and materials and place them into a top loading opening in the truck. The pickup arm assembly includes a turntable mounted on the truck bed adjacent to and rearwardly of the truck cab. A main boom is pivotally secured to the turntable on a horizontal pivot axis, so that the main boom may pivot through approximately 180.degree. in the space between the truck cab and the truck body. A coupling assembly is joined about one axis to the upper end of the main boom, and an intermediate boom is joined to the coupling about another, orthogonal axis. An outer boom is pivotally joined at one end in to a clevis end of the intermediate boom. A clamshell assembly is pivotally secured to the outer end of the outer boom. The turntable is power-driven, and all booms and the clamshell assembly are each manipulated by a power assist device. In a further embodiment, the turntable is supported on laterally extending rails or guides, so that the turntable may be translated laterally to either side of the truck bed. In another embodiment, a rail support extends longitudinally along the upper surface of the truck body and truck cab. A multi-boom pickup arm assembly is supported on a carriage that is adapted to travel along the rail support to permit the pickup arm assembly to engage objects and articles in the front or rear of the truck. In another aspect of the invention, a pickup arm assembly is supported by paired, laterally opposed arms pivotally joined on either side of the truck body to move the arm forwardly or rearwardly.