Considerable evidence demonstrates the importance of the cognitive home environment in supporting children's language, cognition, and school readiness more broadly. This is particularly important for children from low-income backgrounds, as cognitive stimulation is a key area of resilience that mediates the impact of poverty on child development. Researchers and clinicians have therefore highlighted the need to quantify cognitive stimulation; however existing methodological approaches frequently utilize home visits and/or labor-intensive observations and coding. Here, we examined the reliability and validity of the StimQ.sub.2, a parent-report measure of the cognitive home environment that can be delivered efficiently and at low cost. StimQ.sub.2 improves upon earlier versions of the instrument by removing outdated items, assessing additional domains of cognitive stimulation and providing new scoring systems. Findings suggest that the StimQ.sub.2 is a reliable and valid measure of the cognitive home environment for children from infancy through the preschool period.