Abstract A second generation of LWD Nuclear Magnetic Resonance (NMR) tools has been developed and commercialized. These MRI-LWD* (Magnetic Resonance Image - Logging While Drilling) tools extend the technology by providing key improvements in data quality and operational efficiency. Improvements include: automatic mode switching, better vertical resolution, improved signal-to-noise ratio (SNR), real-time data transfer, built-in log quality control, increased battery life, and extended environmental ratings. The paper also examines the context for the deployment of this system and the expanding role of NMR in formation evaluation. MRI-LWD belongs to a family of NMR tools which includes logging-while-drilling, wireline open-hole logging, formation testing/fluid sampling, and laboratory core analysis.