OBJECTIVES: The Conners 3rd Edition–Parent (Conners 3–P) is used to obtain parents’ observations about the behaviors and feelings of children and adolescents aged 6-18 years old. Developed in American English and published by Multi-Health Systems, it was designed to assess Attention Deficit/Hyperactivity Disorder (ADHD). The short version provides the evaluation of inattention, hyperactivity/impulsivity, learning problems, executive functioning, aggression, and peer relations, and includes 43 items rated on a 4-point scale (“Not true at all” to “Very much true”). The objective of this study is to present the challenges faced during the translation of the instrument into ten Indo-European languages (English for four countries, French, Italian, German, Spanish for three countries), one Sino-Tibetan (Chinese), and one Austronesian language (Malay). METHODS: The following translation method was used: 1. Concept definition; 2. Forward/backward translation [or adaptation for English and Spanish versions (i.e., for Argentina and Mexico)]; 3. Review of the back-translations/adaptations by the copyright holder of the instrument; and 4. Cognitive interviews with five parents in each country. RESULTS: The translation process did not reveal any cultural issues since most of the concepts assessed were cross-culturally relevant. The main difficulties consisted in finding conceptual equivalents of the original items with strong idiomatic content. For instance, the most challenging items were items 13 (“Acts as if driven by a motor”), 31 (“Tells the truth; doesn’t even tell “little white lies.”), and 40 (“Behaves like an angel”). Most of the solutions were found using concept definitions. Parents were important in discussing changes or proposing solutions. Examples will be provided. CONCLUSIONS: The multi-step process proved to be critical to ensure the production of conceptually equivalent and culturally appropriate translations of the Conners 3–P into Indo-European, Sino-Tibetan and Austronesian languages. The involvement of the copyright holder and of parents was crucial in finding solutions.