Objective: To explore differences in the factors influencing parents and teachers assessments of preschool children s mental health using the Strengths and Difficulties Questionnaire (SDQ), so as to provide reference for promoting children s mental health. Methods: A retrospective analysis was conducted on the SDQ survey data of 14 763 middle and senior kindergarten children in Nanshan District, Shenzhen, from March to June 2023. Chi square χ 2 tests were used to analyze differences in mental health assessments between parents and teachers. Multivariate Logistic regression was employed to examine the factors influencing parental assessments, and Kappa coefficients were used to evaluate the consistency between parent and teacher evaluations. Results: The positive rate of mental health problems reported by parents (7.2%) was significantly higher than that reported by teachers (6.2%) ( χ 2=254.27, P <0.01). Gender differences revealed that parents reported a lower positive rate for boys (7.9%) compared to teachers (8.5%), whereas for girls, the parental positive rate (6.4%) was higher than that reported by teachers (3.8%) ( χ 2=163.59, 81.26, all P <0.01). Age related differences showed that parental positive rates for 4, 5, and 6 year olds (8.5%, 7.4%, 5.8%) were consistently higher than teachers assessments (6.3%, 6.7%, 5.4%) ( χ 2=41.23, 157.53, 63.67, all P <0.05). Univariate analysis of parental assessments indicated higher positive rates among boys (7.9%), 4 year olds (8.5%), mothers aged 20-35 ( 6.6 %), mothers with high school education or below (9.8%), fathers aged 23-40 (6.4%), fathers with high school education or below (10.3%), and children exposed to secondhand smoke (7.9%) ( χ 2=23.56-235.24, all P <0.01). Multivariate Logistic regression identified lower parental education levels and exposure to secondhand smoke as significant risk factors for abnormal SDQ assessments by parents ( χ 2=2.05, 1.62, 3.15, all P <0.05). The Kappa coefficients for parent-teacher agreement across SDQ subscales and total difficulties ranged from 0.04 to 0.12 (all P <0.01). Conclusions Parental education level and exposure to secondhand smoke are significant factors influencing preschool children s mental health. Differences exist between parental and teacher assessments of children s mental health, and incorporating teacher evaluations can provide a more comprehensive understanding of preschoolers psychological well being.