Two fiber optic DTS systems were deployed and evaluated in oil and gas wells. Extended testing at 5,000 and 3,000 foot depths was performed to characterize the stability of the sensors. Long-term stability of less than 0.4degreesC rms and short-term stability of 0.05degreesC rms were observed. Ease of fiber optic sensor array deployment was proven, as well as the feasibility of remote real time monitoring of downhole temperature distributions.