Although differential ratings by multiple informants are an important issue in survey design, few studies test the degree of difference between informants. This study examined differences in caregiver and teacher ratings of school readiness of children from a disadvantaged urban community in Ireland. School readiness was assessed using the Short Early Development Instrument (S-EDI). Two hundred and twenty-three caregivers and 21 teachers completed a survey for 223 and 224 children, respectively. Caregiver ratings of school readiness were significantly higher than those of teachers across multiple domains and subdomains of school readiness. Most discrepancies remained when the sample was disaggregated according to child gender, teacher experience, and caregiver education. These findings may be due to different frames of reference held by caregivers and teachers or differential child behaviour in the home and school contexts. Thus, contributions of different informants may provide valuable information on the school readiness of children and highlight key areas of importance for early interventionists. (Contains 4 notes, 2 tables, and 1 figure.)