A contact interaction analysis is presented to search for new phenomena beyond the Standard Model in deep inelastic e±p → e±hadrons scattering. The data are collected with the H1 detector at HERA and correspond to integrated luminosities of 0.909 pb-1 and 2.947 pb-1 for electron and positron beams, respectively. The differential cross sections dσ/dQ2 are measured in the Q2 range between 160 GeV2 and 20 000 GeV2. The absence of any significant deviation from the Standard Model prediction is used to constrain the couplings and masses of new leptoquarks and to set limits on electron-quark compositeness scales and on the radius of light quarks. © 1995.