In this work, 91 vapor pressure data of cis-1,1,1,4,4,4-hexafluoro-2-butene (HFO-1336mzz(Z)) were measured using a Burnett apparatus in a temperature range of (278 to 443) K and a pressure range of (30 to 2830) kPa. The sample was analyzed by gas chromatography with mass spectrometry, and the vapor pressure deviations caused by impurities were corrected based on the ideal solution model. The combined expanded (k = 2) uncertainty in the temperature measurement is 6.2 mK, and the combined expanded (k = 2) uncertainty in vapor pressure is (0.30 to 0.90) kPa. On the basis of the literature data and the experimental data in this work, a new Wagner-type vapor pressure equation was used to correlate the experimental data. The normal boiling point temperature of HFO-1336mzz(Z) was estimated to be 306.613 K.