OBJECTIVE: To determine the immediate efficacy of a single session of deep dry needling (DDN) vs ischemic compression (ICT) in a latent myofascial trigger point (MTrP) of the shortened triceps surae from triathletes for ankle dorsiflexion and redistribution of plantar pressures and stability. DESIGN: A randomized simple blind clinical trial (NCT03273985). SETTING: An outpatient clinic. SUBJECTS: Thirty-four triathletes with a latent MTrP in the shortened gastrocnemius. METHODS: Triathletes were randomized to receive a single session of DDN (N = 17) or ICT (N = 17) in a latent MTrP of the shortened triceps surae. The primary outcome was ankle dorsiflexion range of motion (ROM) by a universal goniometer. Secondary objectives were distribution of dynamic and static plantar pressures by T-Plate platform pressure, with measurements both before and after five, 10, 15, 20, and 25 minutes of treatment. RESULTS: There were no statistically significant differences (P > 0.05) for ankle dorsiflexion ROM or dynamic and static plantar pressures between the experimental group treated with DDN and the control group treated with ICT before and after treatment. CONCLUSIONS: DDN vs ICT carried out in latent MTrPs of the shortened gastrocnemius of triathletes did not present differences in terms of dorsiflexion ROM of the tibiofibular-talar joint or in static and dynamic plantar pressure changes before and immediately after treatment.