This study was carried out to evaluate the effect of night irrigation on the eggplant performance with regard to the irrigation adequacy levels and root temperature indicators. The research site was the Agricultural College of Ferdowsi University of Mashhad. Plant irrigation was conducted through drip irrigation and the soil texture was loam according to tests. Experiments were conducted in a randomized complete block design with three treatments and six replications. The results of statistical analysis showed that night irrigation was significant on the crop performance and water use efficiency (WUE) at 5% confidence level. The amount of consumed water in day and night irrigation was equal. However, the night irrigation performance at the levels of adequacy of 100, 75 and 50% was, respectively, 3.77, 3.69 and 3.07 kg in 2012, and 2.50, 1.95 and 1.60 kg in 2013 more than day irrigation. Irrigation timing (night and day) was affected by root temperature difference. In addition, the temperature after day irrigation increased, but decreased in night irrigation.