A search for pair-production of supersymmetric particles under the assumption that R-parity is violated via a dominant LQD¯ coupling has been performed using the data collected by ALEPH at centre-of-mass energies of 130–172 GeV. The observed candidate events in the data are in agreement with the Standard Model expectation. This result is translated into lower limits on the masses of charginos, neutralinos, sleptons, sneutrinos and squarks. For instance, for m0=500 GeV /c2 and tanβ=2√ charginos with masses smaller than 81 GeV /c2 and neutralinos with masses smaller than 29 GeV /c2 are excluded at the 95% confidence level for any generation structure of the LQD¯ coupling.