OBJECTIVES: The Asthma Control Questionnaire (ACQ) was developed and validated to measure the adequacy of asthma control in patients 11-70 years. Younger children have difficulty reading and understanding the instructions, questions and response options. For 6-10 year olds, an interviewer version (ACQ-IA), with instructions on explaining the time specification and interval scale, was developed and validated in UK English. If a child has difficulty understanding an ACQ question, standardised alternative wording is used. The objective was to develop the ACQ-IA in Spanish for Guatemala and Peru, languages in which the adult ACQ already exists, using the methodology developed for the UK ACQ-IA. METHODS: In each language, the following methodology was used: 1) Forward and backward translation of the UK ACQ-IA instructions; 2) Cognitive debriefing with children (n=5) to test the instructions and to identify ACQ questions that were difficult to comprehend; 3) Development of alternative questions in the new language; 4) Developer’s review; 5) Testing of the alternatives on another sample of children (n=5); and 6) Developer’s review. RESULTS: In both languages, items 1, 2, 3 and 6 required the development of alternatives, because of difficulties in understanding words such as “asma” (asthma), “intensos” (strong), or actividades (activities). In both languages, the wording of the adult version of item 4 (“…how much shortness of breath did you experience because of your asthma?”) was well understood and did not require the development of alternative wording. Item 5 (“…how much time did you wheeze?”) was problematic in Peru, but not in Guatemala. Children had difficulties with ‘wheeze’ (“te ha silbado el pecho”). The wording used by mothers, “te ha sonado el pecho” was more easily understood by children. CONCLUSIONS: The validity of this novel methodology for the cultural adaptation ACQ-IA has been further supported by these successful adaptations for Peru and Guatemala.