This research was conducted to determine the water requirements of the pineapple crop (Ananas comosus L.), cv. “Pérola” grown in the Coastal table lands of Paraíba state, Brazil, using a sprinkler irrigation system as complementary water supply. A micrometeorological tower was mounted in a 90m×90m experimental area for determining energy fluxes in the interface plant/soil-atmosphere. Crop evapotranspiration (ET_c) was estimated by the Bowen ratio-energy balance and reference evapotranspiration (ET_o) by the Penman-Monteith method. The mean daily crop evapotranspiration was too variable throughout the pineapple crop development cycle, with values decreasing from (ET_c=4.6mmday⁻¹) in the vegetative growth to 3.5mmday⁻¹ in the fruits harvesting phenological stage. On the overall, ET_c was lower in the beginning of the vegetative growth and fruits harvest and higher in the middle of the productive cycle. The cumulative water used during the crop growing cycle was 1421mm while the cumulative reference evapotranspiration was 1614.9mm. Lower values of the crop coefficient (K_c) were observed during the vegetative growth (phase II) stage while for the whole crop cycle, K_c=0.88±0.06. This result can be used for a most efficient water use and to optimize production of the pineapple crop grown in tropical environments, particularly in Coastal table lands of Paraíba state, Brazil.