Distributed Temperature Measurements (DTS) have been used in the oilfield now for over 10 years, with the majority of applications requiring the fiber to be installed permanently in the well, either inside a 1/4-in control line or as part of an electrical gauge cable. A slickline 1/8-in diameter wire has now been developed with an optical fiber embedded inside it so that DTS measurements can be performed during a conventional slickline operation. This new approach to temperature monitoring means that the optical fiber can now be deployed temporarily in a producer or injector well only when needed, using a conventional slickline unit which can also run a bottomhole pressure gauge or a production log at the same time. The ability to monitor the whole well with DTS using a slickline intervention installation allows the operator to use this technology to resolve a range of well integrity, production and stimulation problems. This paper highlights the use of fiber-optic slickline monitoring in Texas and New Mexico over the past two years by discussing a number of field cases that show the application of this technology for monitoring well integrity and diagnosing well problems, how the DTS can be used to evaluate the fracture height created by a fracture job, determining the effectiveness of the stimulation in acid stimulation operations and also how the data can be used to monitor water injection in low rate injector wells. Because the fiber is deployed and data is acquired on a "when needed" basis, it is proving much more economical than a permanently installed optical fiber, and can bring the benefits of this monitoring technology to a greater number of wells.