Objective: This study aimed to improve healthy sleep habits among children aged 5-6 years through nursing interventions.,Materials and Methods: This was a quasi-experimental study with a pretest-posttest design including a control group. The study was conducted in two preschool education institutions that were affiliated with the Ministry of National Health in Zonguldak city between February and May during the 2018-2019 academic year. Data were collected using a descriptive questionnaire form, health education scale for preschool children and healthy sleep habit development program for 5-6-year-old children.,Results: Findings in the intervention group were as follows: mean sleep duration, 10.5 +/- 0.82 h; mean daytime sleep duration, 2.00 +/- 0.85 h; mean sleeping hours on weekdays, 21.28 +/- 0.75 h; mean sleeping hours on weekends, 22.20 +/- 0.75 h; number of nocturnal, 0.92 +/- 1.12. Findings in the control group were as follows: mean sleep duration, 9.84 +/- 0.73 h; mean daytime sleep duration, 2.02 +/- 0.44 h; mean sleeping hours on weekdays, 21.59 +/- 0.74 h; mean sleeping hours on weekends, 22.25 +/- 0.86 h; number of nocturnal awakenings, 1.25 +/- 0.55. A significant difference was found between pre-education and post-education scale scores in the intervention group (p=0.002), but no significant difference was found in the control group.,Conclusion: Nursing interventions using a healthy sleep habit development program might be effective in developing healthy sleep habits among children aged 5-6