We demonstrate a microfluidic device based on the inductive Coulter counting principle for detection of metallic wear debris in lubrication oil; such debris particles can be indicative of potential machine faults in rotating and reciprocating machinery. The device detects the passage of individual ferrous and non-ferrous debris particles by monitoring inductance change of a planar coil embedded in a microchannel. Testing results show the device is capable of detecting and distinguishing ferrous and non-ferrous metal particles in lubrication oil as small as 50 μm. This development could lead to real-time debris monitoring devices for real-time detection of machine component wear, provide valuable information on the progression of machine wear, and therefore can eliminate the need for costly machine shutdowns for inspection, and avoid the possibility of catastrophic component failure during operation.