The emperor Nero was the first to attempt to construct the canal, personally breaking the ground with a pick-axe and removing the first basket-load of soil in 67 CE, but the project was abandoned when he died shortly afterwards. The Roman workforce, consisting of 6,000 Jewish prisoners of war, started digging 40–50-metre-wide (130–160 ft) trenches from both sides, while a third group at the ridge drilled deep shafts for probing the quality of the rock (which were reused in 1881 for the same purpose). According to Suetonius, the canal was dug to a distance of four stadia (approximately 700 meters (2,300 ft); about a tenth of the total distance across the isthmus). A memorial of the attempt in the form of a relief of Hercules was left by Nero's workers and can still be seen in the canal cutting today. Other than this, as the modern canal follows the same course as Nero's, no remains have survived.

The Venetians also considered it in 1687 after their conquest of the Peloponnese but likewise did not initiate a project.