Self-talk is a psychological and cognitive product of humans that correlates with stress-related variables, such as anxiety and depression. The immediate effects of positive self-talk on stress (in terms of cortisol reactivity) and speech performance have yet to be investigated. Thus, the author examined the immediate effects of positive self-talk on stress and speech performance. The roles of dispositional and speech-related inner self-talk were also investigated. One hundred and forty participants were assigned to Control, Stress Alone, Positive Self-Talk, or Distraction conditions. A standardized stress-inducing task was used for the experimental groups. Participants in the Positive Self-Talk condition rehearsed a positive self-statement during the experiment, and a distraction task was completed by those in the Distraction condition. Saliva samples were collected for cortisol analysis, and questionnaires were administered to assess participant perceived stress levels and inner self-talk. Immediate effects of positive self-talk on cortisol reactivity, perceived stress, and speech performance were absent. Nevertheless, speech-related positive inner self-talk was inversely correlated with the perceived stress level. Furthermore, negative inner self-talk was also related to cortisol reactivity, perceived stress, and speech performance.