[en] I report on some of the more important results from high energy electron positron collisions at PETRA. These results come from the data collected over the last three years by five experiments: CELLO, JADE, MARK-J, PLUTO and TASSO. Topics include measurements of the electroweak interactions of leptons and quarks and searches for the source of electroweak symmetry breaking. The purely leptonic interactions, Bhabha scatering, muon pair production and tau pair production have been studied in detail. Experiments at PETRA have observed weak neutral current effects by measuring the forward backward charge asymmetry in muon pair production to an accuracy of better than 2% at q₂ of approximately 1200 GeV₂. The data are interpretted in terms of sin₂THETAsub(w) in the standard model and gsub(A), gsub(v) and C in more general models of electroweak interactions. Using measurements of R, we make a more accurate determination of sin₂THETAsub(w) at high q₂. Technipions, charged Higgs particles, and supersymmetric scalar particles have been searched for up to masses of 15 GeV. Quantum chromodynamics is found to be in excellent agreement with the distributions of three jet events and αsub(g) is measured using second order perturbative QCD calculations. (orig.)