The current-density profile in the core of a high-temperature reversed-field pinch plasma (RFP) was measured. Plasma conditions considered were sawtooth oscillation in standard RFP plasma and improved confinement pulsed parallel current drive plasmas (PPCD). A high-speed Faraday rotation polarimetry system was developed to measure the internal magnetic field from which the current density was evaluated. Results indicated that the current density flattened during the crash phase of the sawtooth cycle, and peaks during the slow ramp phase of the cycle.