Using data for 4th graders in primary schools from the Progress in International Reading Literacy Study (PIRLS), I compare across 25 countries the ways in which home literacy environments influence children's reading performance. Examined are three indicators: early home literacy activities, parental attitudes toward reading, and number of books at home. The Ordinary Least Squares (OLS) regression analyses show that the 3 measures of home literacy environments positively affect children's reading performance in almost all countries, while the strength of the effects varies substantially across countries. The extent to which the effect of parental education on children's reading is mediated by home literacy environment is only modest except for a few countries. Finally, multilevel models show that the effects of early home literacy activities and parental reading attitudes vary across countries according to their levels of economic development, while the effect of number of books shows the U-shaped relationship with the economic level. (Contains 4 tables, 1 figure and 5 notes.)