In the present study we examined the influence of question format and age on Iranian children’s responses to various types of yes-no questions, to assess potential response biases. The participants were 177 2-to 6-year old native speakers of Persian who were asked both positively and negatively formulated yes-no questions about eight household objects. The results showed that children of different ages are influenced differently by the way questions are formulated. The findings also suggest that children display a compliance tendency when asked yes-no questions. That is, they tend to respond to yes-no questions in the direction implied by the question: ‘yes’ to positively worded questions and ‘no’ to negatively worded questions. This tendency, however, seems to grow weaker as children get older.