This study investigates how durational patterning at discourse boundaries (duration of utterance-final syllables, silent pause, and speech rate) is related to therapist empathy in psychotherapy. Four psychotherapy sessions each from 39 therapist-client dyads conducted in Cantonese were videotaped, transcribed, and analyzed. Clients rated therapist empathy using the Barrett-Lennard Relationship Inventory (BLRI). Mixed-effects regression showed significant effects of silent pause and speech rate on BLRI. The shorter the silent pause or the faster the speech rate, the higher the therapist empathy. Additionally, there were significant interaction effects of the duration of utterance-final syllables with silent pause and speech rate respectively. For the same unit of increment in the duration of utterance-final syllables, shorter silent pause or faster speech rate was predicted to have a greater magnitude of improvement in therapist empathy than longer silent pause or slower speech rate. Also, the interaction between silent pause and speech rate was significant. For utterances with fast (slow) speech rates, the longer the silent pause, the lower (higher) the therapist empathy. Our results have shown that clients integrated low-order durational patterning at the discourse boundaries in their higher-order perception of therapist empathy, which have clinical/educational implications for the use of prosody in psychotherapy.