This book explains the differences and similarities of animal-related idioms in English and Bosnian. The book objective is to analyse animal–related idioms in the English language and to compare them with their Bosnian equivalents using contrastive analysis method. In addition to these idioms we have also tried to translate English idioms related to animals without their equivalents in Bosnian and vice versa. Many differences and similarities were found in the idioms of both languages. They differ in the choice of animal terms, different lexemes and usage. On the other hand, these idioms can be very similar or even the same in their form and meaning. However, their purpose in the language is always the same and that is to make the language richer and better. Hopefully this research will help foreign language learners better understand idioms of either English or Bosnian languages.