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In previously reported double-blind experiments, electrodermal activity (EDA) monitored during display of randomly selected photographs showed that EDA was higher before emotional photos than before calm photos (p ¼ 0.002). This differential effect, suggestive of precognition, was dubbed ''presentiment.'' Three new double-blind experiments were conducted in an attempt to replicate the original studies using the same basic design, but with new physiological monitoring hardware, software, stimulus photos, subject populations, and testing environments. The three replications involved 109 participants who together contributed 3,709 trials. The new studies again showed higher EDA before emotional photos than before calm photos (p ¼ 0.001). All four experiments combined involved 133 participants and 4,569 trials; the associated weighted mean effect size (per trial) was e ¼ 0.064 6 0.015, over 4 standard errors from a null effect. As a more general test, presentiment predicts a positive correlation between pre-stimulus EDA and independently assessed emotionality ratings of the photo targets. The observed correlation across all four experiments was significantly positive (p ¼ 0.008). Consideration of alternative explanations, including expectation, sensory cues, hardware or software artifacts, inappropriate analyses, and anticipatory strategies, revealed no suitable candidates that could systematically generate the observed results. This series of four experiments, supported by successful replications conducted by other investigators, appears to demonstrate a small magnitude but statistically robust form of precognition in the human autonomic nervous system.