The study examines factors underlying cross-language transfer in bilingual children; the main focus is on a measure of metaphor interpretation. Subjects were Spanish-English children ranging in age from 7 to 12 years. Measures were obtained for nonverbal mental capacity, metaphor interpretation, verbal-conceptual repertoire, and linguistic proficiency in English and Spanish. Using a previously validated procedure, subjects' metaphor interpretations were scored for cognitive complexity. In both languages, metaphor score was higher in older than in younger children. Correlational analyses indicated that level of metaphor interpretation was most strongly related to cognitive-developmental variables that are interdependent across languages, that is, nonverbal mental capacity and verbal-conceptual repertoire. Variables that measure specific proficiency in a language were less strongly related to level of metaphor interpretation, and did not exhibit cross-language correlations. This pattern was clearly seen in results of exploratory factor analyses. The role of cognitive versus linguistic factors in metaphor development is discussed, as is the issue of interdependence versus independence across first and second languages.