The thermal conductivity of H2O + CoCl2 solutions was measured over the temperature range 293 to 473 K using a parallel-plate apparatus. Data cover the pressure range from 0.1 to 100 MPa. Measurements were made on ten isotherms, namely: 293, 313, 333, 353, 373, 393, 413, 433, and 473 K. The concentrations studied were 2.5, 5, Ill, 15, 20, and 25 wt % CoCl2,. The uncertainty of thermal conductivity measurements was estimated to be +/-1.6%. The pressure effect on thermal conductivity behavior was similar for H2O and H2O + CoCl2. In the temperature range of our experiments, isotherms of thermal conductivity were almost linear function of pressure at all temperatures for each concentrations. Along each isobar a given concentration the thermal-conductivity of H2O + CoCl2 solutions exhibits a maximum at temperatures between 405 and 419 K. The measured values of thermal conductivity are compared with the experimental and correlation results of other investigators. A new correlation which yields the correct temperature, pressure, and concentration behavior of thermal conductivity is proposed. This maximum is displaced to higher temperature when the pressure is increased at each compositions. For fixed pressure the maximum is displaced to Lower temperature when the composition is increased.