This research examined the effectiveness of Multipurpose Unit Early Classroom Intervention Program (MUECIP) prepared for 4-5-year-old (48-60 months) children whose development is at risk because of their families' socioeconomic conditions. The research adopted a preliminary test-final test control group trial model. The research participants were children born in 2006 and living in Center of Canakkale Province and Kepez Town in the 2010-2011 academic year. There were 28 children in the study group, 14 of whom were studying at the Canakkale Onsekiz Mart University CABA Multipurpose Early Childhood Classroom Unit and 14 of whom were studying at the Kepez Municipality Preschool Education Classroom. The groups were examined using the Children and Family Recognition Survey, Raven Progressive Matrix Test, Denver II, and Development Assessment Observation Form for 48-60 month old children. Preliminary test results and non-parametrical techniques were used to analyze the data. In the experimental group, MUECIP was conducted by the researcher 4 half days a week for 13 weeks, and for the control group, the Ministry of Education Preschool Education Program (2006) was conducted using traditional methods. The results indicated that MUECIP was effective in increasing general development levels, cognitive and psychomotor developments, self-care skills and partially effective in improving the language and personal-social development skills of the children. It is recommended that the prepared MUECIP be spread more widely and promoted as an alternative model in the early education of children from lower socioeconomic families.