A child's first book is a picture book that combines verbal and visual information. The quality of a picture book largely depends on how well the visual and the verbal part support each other, the more they do, the better the quality. Experts have proven that reading picture books develops cognitive functions such as judgement, reasoning, reading, listening, speaking and non-verbal communication. The main objective of this dissertation is to research different illustrations of the same picture book – Kozlovska sodba v Višnji Gori, to determine the quality of illustrations and children's respond to different illustrations. My main interest was to see whether children respond better to a quality illustration. The research included 20 children, 10 boys and 10 girls, aged from 7 to 8, from the second year of elementary school Osnovna šola Ferda Vesela Šentvid pri Stični. The prevailing research method was an interview where schoolchildren answered my questions about the illustrations and I noted their answers. Children's answers and responses are presented in tables. The results show that Gabrijel Vrhovec's illustrations contain the most elements of lower-quality illustrations, nevertheless all four illustrations still meet the quality illustration criteria. Schoolchildren expressed their subjective opinion of illustrations, paying specific attention to displayed details. They responded better to an illustration that was of poorer quality.