Purpose: The aim of this study is to investigate how speech fluency in typical and atypical speech is perceptually assessed by speech-language pathologists (SLPs). Our research questions were as follows: (a) How do SLPs rate fluency in speakers with and without neurological communication disorders? (b) Do they differentiate the speaker groups? and (c) What features do they hear impairing speech fluency? Method: Ten SLPs specialized in neurological communication disorders volunteered as expert judges to rate 90 narrative speech samples on a Visual Analogue Scale (see Kempster, Gerratt, Verdolini Abbott, Barkmeier-Kraemer, & Hillman, 2009; p. 127). The samples--randomly mixed--were from 70 neurologically healthy speakers (the control group) and 20 speakers with traumatic brain injury, 10 of whom had neurogenic stuttering (designated as Clinical Groups A and B). Results: The fluency rates were higher for typical speakers than for speakers with traumatic brain injury; however, the agreement among the judges was higher for atypical fluency. Auditory-perceptual assessment of fluency was significantly impaired by the features of stuttering and something else but not by speech rate. Stuttering was also perceived in speakers not diagnosed as stutterers. A borderline between typical and atypical fluency was found. Conclusions: Speech fluency is a multifaceted phenomenon, and on the basis of this study, we suggest a more general approach to fluency and its deviations that will take into account, in addition to the motor and linguistic aspects of fluency, the metalinguistic component of expression as well. The results of this study indicate a need for further studies on the precise nature of borderline fluency and its different disfluencies.