African urban youth language (AUYL) syndrome is a sociolinguistic phenomenon. Its most distinguishing symptom is the investment of African youths in a stigmatized variety to the exclusion of more prestigious languages. AUYLs have long stumped educators, policy makers and teachers of standard languages, spawning cursory descriptions, numerous complaints, and pleas for eradication. A case study of the symptoms associated with the stigmatized code Sheng (Nairobi, Kenya), reveals generalities for other AUYLs. Detractors worry that embracing the variety will damn the youth to failure in examinations, to denial of further educational attainment, to the loss of life-long goals, such as social mobility, and perhaps even to criminality. This article examines the concept of the culture-bound syndrome-a collection of social symptoms that reflect cultural fears-and the manner in which it may be applied to Sheng and other AUYLs. An interdisciplinary exploration of colonial history, language ecosystem, language ideology and conventional wisdom provide a rationale for a sociolinguistic defense. The data disclose that the symptoms reveal more about the plaintiff than the defendant. Overcoming what is but a standard language ideological bias requires Africanists in all academic disciplines to legitimize AUYLs through continued research.