The structural integrity and predictable usability of slickline wire has perplexed wireline crews since wireline services were first developed, Miscalculation of wire condition can cause wire failures and costly fishing operations. However, the available alternative-premature replacement of still-usable wire to avoid the first scenario-increases operational costs, especially when the newer corrosion and embrittlement-resistant nickel and cobalt alloy wires that are commonly used in H2S, CO2, and hot chloride environments are involved. These wires often are ten times as costly as carbon steel and stainless steel alloy wires, and in most cases, early replacement would not be economically feasible. Until recently, operators have had to rely on experience, "rules of thumb," visual inspection, and destructive tests to determine wire integrity. However, these methods could only provide spot checks; no methods have been capable of accurately assessing the condition of the entire length of spooled wire. This paper will review currently used inspection procedures and a concept that incorporates an existing, non-destructive material inspection technology into a real-time method that can provide the information to determine wire condition over its entire length. Use of this eddy current system can: Evaluate integrity of new wire as it is being spooled onto the reel. Avoid costly replacement of still-usable wire. Facilitate general wire-life assessment. Inspect wire during critical service operations where well environment or operating conditions can cause rapid degradation of the wire. Test results and field operational history are used to illustrate the capabilities and significance of the system.