Production of horticultural crops is important throughout the world, with high consumption mainly in Europe and the United States of America. Cucumber is consumed both fresh and processed. This vegetable generates important profits for producing countries such as Mexico, which, in 2003, produced 435,897 tons of fresh fruit with a value of 1.190 million Mexican pesos (around USD $109 million). The objective of this work was to evaluate the effect of the floating cover on the yield of fresh cucumbers. Four treatments and five repetitions were imposed in a randomized distribution: covered 20 days (C20) post-emergence, covered until beginning of flowering (CF), covered until beginning of harvest (CIC), and without cover (SC). Data at the first and fourth harvest were analyzed. Results showed that, in the first harvest, treatment C20 days was highest in fruit yield (3.11 ton/ha); Treatment CIC had 2.47 ton/ha, and SC produced 1.66 ton/ha. Data obtained in the fourth harvest, treatment C20, had the highest yield, with 24.12 ton/ha, and treatment CF had a yield of 21.11 ton/ha, but there was not significant difference (Tukey's P < 0.05).