This study reports the results of an investigation of public awareness and knowledge of stuttering in Rio de Janeiro, Brazil. A total number of 606 street recruited respondents answered questions on various aspects of stuttering, including prevalence, onset, gender distribution, occurrence in different cultures, cause, treatment, intelligence, and hereditariness. The questionnaire used was a Portuguese version of the one by [Van Borsel, J., Verniers, I. & Bouvry, S. (1999). "Public awareness of stuttering." "Folia Phoniatrica et Logopaedica," 51, 124-132]. Although, stuttering is a disorder which is known to a majority of the participants, knowledge appears to be limited for certain aspects. Knowledge also differs among subgroups of participants according to gender, age and educational level. Comparison of the results of the current study with similar studies conducted in Belgium and in Shanghai, China shows several similarities but also some differences. Educational objectives: The reader will be able to: (1) discuss public awareness and knowledge of stuttering in Rio de Janeiro, Brazil; (2) discuss the differences in knowledge according to gender, age and educational level and; (3) discuss similarities and differences with comparable studies run in Belgium and Shanghai, China. (Contains 5 tables.)