Background: The first year of life is the most important period of an extra uterine brain development requires environmental stimulation for developmental capabilities expression. Mean while, due to the repeated environmental disparity, nursery children are at great risk of developmental delay. Aim: To determine the effect of an evidence-based care package on infant gross motor development. Methods: In this randomized clinical trial, conducted at Ali Asghar (AS) nursery of Mashhad, an evidence-based care package was utilized. Fifty babies with the age of 12-1 months eligible according to inclusion criterion were randomly divided into the intervention (25 infant) and control (25 infant) groups. Then, the care package was administered for children in the intervention group, three times a week for 8 consecutive weeks (24 sessions, each two hours). Gross motor developmental age of the children was assessed by the Denver-II, before the intervention, 6 and 8 weeks after the intervention. The results were analyzed with SPSS 11.5 software using independent t-test, Mann-Whitney U and repeated measures ANOVA. Results: The mean age of the sample was 20.64 ± 14.62 years and 32% of total were female and 68% male. The average of the gross motor age were 21.4±7.9 and 15.8±13.0 years in the intervention and control groups (P>0.05), respectively. After 6 weeks implementation of the care package, the difference of the mean of the gross motor age between the intervention (26.5±10.8) and control groups (21.4±11.4) was not statistically significant (P=0.115). Two weeks later (8th weeks), the difference of the mean of the gross motor age in the intervention group (29.4±10.5) and control group (22.9±10.3) was statistically significant (P=0.033). Conclusion: Six weeks intervention by this evidence-based care package is not effective on the infant's gross motor development. This effect was determined after 8 weeks of an intervention. This package can be used to improve gross motor skills in infants at risk of developmental delay such as infant sliving inorphanages.