Abstract: A new and improved adjustable ratchet wrench apparatus includes a handle assembly and a wrench head assembly which includes a ratchet assembly and a jaw assembly. The ratchet assembly includes a ratchet assembly housing connected to the handle assembly. The ratchet assembly housing is substantially C-shaped and includes a first free-ended portion and a second free-ended portion. A first gap is provided between a first free end of the first free-ended portion and a second free end of the second free-ended portion. The ratchet assembly includes a first ratchet element supported by the ratchet assembly housing. The first ratchet element permits unidirectional rotation of the jaw assembly. The jaw assembly includes a substantially C-shaped jaw assembly housing which is nested within and is supported by the ratchet assembly housing for relative rotation between the ratchet assembly housing and the jaw assembly housing.