This investigation was conducted at the Experimental Irrigation Area (AER, Spanish acronym) of La Molina, Peru, at an altitude of 243.7 m.a.s.l. The crop evapotranspiration (CET) was estimated for the IR 71706 rice variety using information obtained from a drainage lysimeter, and the reference evapotranspiration was calculated using the FAO Penman-Monteith method using information obtained from a Davis automatic weather station during the cultivation period from December 2017 to April 2018. Daily readings of irrigation, ground moisture variation, and precipitation were recorded to achieve soil moisture balance and thus determine the CET and crop coefficient (Kc) during the cultivation cycle. A maximum CET of 9.19 mm d–1 was obtained during the reproductive phase (spindle and flow state), a minimum CET of 1.35 mm d–1 during the final crop stage, and an average value of 5.02 mm d–1, and total CET of 658.23 mm with 587 clusters m–2, with an average height of 0.80 m. The initial, mean, and final Kc were 0.9, 1.70, and 0.84, respectively.