Objective: This randomized, controlled clinical study aimed to evaluate the performance of one universal adhesive applied with etch-and-rinse or self-etch strategy and one etch-and-rinse adhesive on fissure sealant retention over 24 months. Methodology: 144 sealants were placed on the permanent premolars and molars of 13 subjects. Teeth were divided into three groups SB2(control): Adper Single Bond 2, SBU-ER: Single Bond Universal/etch-and-rinse, SBU-SE: Single Bond Universal/self-etch. After the adhesive application, Fissurit FX was applied and light-cured. Clinical evaluations were done at baseline and at 1 week, 6-, 12-, 18- and 24-month recalls. Visual examination was performed on every visit for evaluation of the sealants. Evaluating criteria were: 1= completely retained; 2= partial loss; 3= total loss. The Pearson Chi-square test was used for each evaluation period.