The purpose of the study was to investigate the relationships among preschool teachers&rsquo / and preschoolers&rsquo / parents&rsquo / developmentally appropriate practice (DAP) and developmentally inappropriate practice (DIP) beliefs in relation to parental involvement attitudes and perceived parental involvement barriers. To reach to the purposes of the study, data were collected from 279 teachers and 589 parents via a demographic information questionnaire and two main data collection instruments. The demographic information questionnaire aimed to obtain information about the participant&rsquo / s gender, age and educational level. In order to collect information from teachers and parents regarding their beliefs about developmentally appropriate practice / Teachers&rsquo / Beliefs Scale (TBS) (Burts et al., 2000) and the parent adaptation of the scale, Parents&rsquo / Beliefs Scale (Yen, 2008) were used. To ascertain parents&rsquo / and teachers&rsquo / attitudes and the barriers on parental involvement, the School and Family Partnerships Questionnaire (Epstein &amp / Salinas, 1993) was used. The investigation of the relationship between the teachers&rsquo / and parents&rsquo / DAP and DIP beliefs in relation to their parent involvement attitudes (PIA), parent involvement barriers (PIB) revealed significant results. The findings of the study revealed that both the teachers&rsquo / and parents&rsquo / PIA and PIB made significant contributions to their DAP and DIP beliefs. As found in the current study, the interaction between the teachers and parents should be increased to help children develop in the most appropriate way. In order to increase this relationship, a detailed focus on the parental involvement paradigm should be undertaken.