To provide a metal working fluid composition affording practically satisfiable emulsion stability, lubricity and defoaming properties and reducing problems of emulsion deterioration by an increase in metal ions during metal working without containing an alkylphenol ethoxylate.

The metal working fluid composition comprises at least a compound in which an alkylene oxide is added to one or two or more kinds of alkenylphenols represented by general formula (1) (wherein, R represents a 13-17C alkenyl group; AO represents a 2-4C oxyalkylene group; n is an integer of 1-100; and n AOs may be same or different) in a base oil for a lubricating oil.