BACKGROUND: Overt attempts at self-correction of speech errors reflect conscious monitoring of speech output. The ability to monitor speech reveals something about the dynamics of motor control. Speakers with apraxia of speech (AOS) attempt to self-correct speech, but systematic analyses of self-correction in AOS have rarely been done. AIMS: The aims of the study were to determine the effect of treatment on the number of overt attempted self-corrections during the course of treatment, on the number of overt attempted self-corrections as a percentage of the total number of incorrect productions, and on successful self-corrections as a percentage of the total number of self-corrections. METHODS and PROCEDURES: One speaker with AOS was treated for a period of 18 months. Self-corrections were noted during three repetitions of 110 words and 110 nonwords. Three pre-treatment baseline probes and four subsequent probes, spanning the treatment period, were performed. OUTCOMES and RESULTS: The number of attempted self-corrections decreased and the percentage of successful self-corrections increased during treatment. However, attempted self-corrections as a percentage of the total number of incorrect productions remained fairly stable during treatment. CONCLUSIONS: The results indicate that success of overt self-corrections improved during treatment. However, the almost unchanged number of self-corrections as a percentage of the total number of incorrect productions suggests that the process of internal predictive control remained dysfunctional. The inadvertent occurrence of speech errors points towards a loss or dysfunction of volitional control of speech production. Mental practice as a complementary treatment technique may need to be considered. A continuum of volitional control of speech is presented to explain AOS.