The invention concerns novel hydroxyalkanoic acid derivatives of the formula: ##STR1## in which A is a straight or branched chain (2-6C)alkylene, R.sup.1 and R.sup.2 are independently hydrogen or (1-6C) alkyl, and R.sup.3 is hydrogen or (1-6C)alkyl, and when R.sup.3 is hydrogen, base-addition salts thereof; and processes for their manufacture. The compounds possess useful anti-arthritic properties and the invention also concerns pharmaceutical compositions of such compounds for use in the treatment of arthritic joint diseases. A representative compound of the invention is 2-2-[4-(4-chlorophenyl)phenyl]-ethoxy}propionic acid.