Children spend a considerable portion of their time indoors. Therefore, homes and schools are an important source of allergen exposure. Chronic exposure to the major indoor allergens can lead to allergic sensitization and provoke allergic symptoms in children. Environmental assessment is crucial for the identification and quantification of such allergens in indoor spaces. Reduction of allergen exposure below sensitization and symptom thresholds is possible with various remediation techniques. This article reviews and discusses evidence for the assessment and remediation of indoor allergens commonly found in homes and schools. A literature review was performed using the PubMed database for English-language articles published between January 1, 1980, and February 2009. Additional information was obtained from a review of recent textbooks and one professional society's webpage.