Urinary tract infections (UTIs) are common diseases that have a considerable impact on the quality of life of patients, and high social and economic burden. However, more evidence on basic and clinical aspects of UTIs is still needed, and big challenges remain – notably the increase in antimicrobial-resistant strains that are causative agents for UTIs, and where appropriate use of antimicrobial agents has a crucial role. The seven chapters of this book tackle key issues in UTI management, such as problems in diagnosis, new diagnostic approaches and management in pediatric UTIs, and the new concept of proper use of antimicrobials.