Diphenoxyacetic acid derivatives of the general formula ##STR1## wherein R.sub.1 is H or alkyl of 1-4 carbon atoms, R.sub.2 is H or Cl, R.sub.2 is H or Cl, R.sub.3 is piperidino, 4-piperidinophenyl, 1,2,3,4-tetrahydroquinolino, 1-R.sub.4 -1,2,3,4-tetrahydro-4-quinolyl, 4-oxo-1,2,3,4-tetrahydroquinolino, 4-chromanyl, 4-thiochromanyl or 4-chlorophenoxy, and R.sub.4 is H or alkyl of 1-4 carbon atoms, and the physiologically acceptable salts thereof, possess cholesterol level lowering activity and can be prepared by reacting a phenol of the formula ##STR2## with a compound of the formula ##STR3## wherein X is OH, esterified OH, Cl, Br or I, one R is R.sub.2 and the other is R.sub.3 ; or by cyclizing a compound of the formula ##STR4## wherein X.sub.1 is Cl, Br, I, NH.sub.2 OH or an esterified or etherified OH-group and n is 0 or 1; or by treating a compound of the formula ##STR5## wherein Z is a functionally modified carboxyl group different from COOR.sub.1, with a solvolyzing agent, R.sub.1, R.sub.2 and R.sub.3 in each instance having the values given above.