We present data characterising the performance of the Mopra Radio Telescope during the period 2000-2004, including measurements of the beam size and shape, as well as the overall beam efficiency of the telescope. In 2004 the full width half maximum of the beam was measured to be 36+/-3'' at 86GHz, falling to 33+/-2'' at 115GHz. Based on our observations of Jupiter we measured the beam efficiency of the Gaussian main beam to be 0.49+/-0.03 at 86GHz and 0.42+/-0.02 at 115GHz. Sources with angular sizes of ~80'' couple well to the main beam, while sources with angular sizes between ~80'' and ~160'' couple to the both the main beam and inner error beam. Measurements indicate that the inner error beam contains approximately one-third the power of the main beam. We also compare efficiency corrected spectra to measurements made at similar facilities and present standard spectra taken towards the molecular clouds Orion-KL and M17-SW.