This chapter focuses on food neophobia, defined as a fear or reluctance to try not only strictly new food but also food that is perceived as new, even if the person has previously encountered it. When analyzing food neophobia, it should be emphasized that it can be viewed both as a natural stage of development and as a feeding and eating difficulty that can significantly affect health at various stages of life. This chapter describes this concept in detail, addressing the ethology, health-related outcomes, and consequences of food neophobia. It also provides selected statistics on the prevalence of food neophobia, compares it with avoidant/restrictive food intake disorder (ARFID), describes methods for measuring food neophobia, and discusses guidelines and recommendations for practice. The topics covered in this chapter indicate that food neophobia should be analyzed by researchers from many different disciplines (including psychology, biology, and nutrition), and its understanding and management require a broad and interdisciplinary approach, including cooperation among dieticians, doctors, and psychologists.