With the help of two cases and written in question and answer format this chapter presents a broad discussion on primary amenorrhea. Primary amenorrhea is considered when a girl has not menstruated by the age 14 years and also lacks other evidence of pubertal development like absence of pubic hair and breast development. She has not menstruated by the age 16 even in the presence of other pubertal signs. There are many ways in which primary amenorrhea is classified. The two commonly used classifications are clinical classification and classification system presented by WHO. The clitoral index is the product of the sagittal and transverse diameters of the glans of the clitoris in the anteroposterior and transverse diameter. Kallmann’s syndrome can be inherited as a C-linked, autosomal dominant or autosomal recessive disorder. The characteristics include delayed development of secondary sexual characteristics, anosmia, and is difficult to distinguish from constitutional delay.