The aged Polycarp of Smyrna, a disciple of John the Evangelist, visited Rome to discuss the celebration of Passover with Pope Anicetus, according to Irenaeus.

Polycarp and his Church of Smyrna celebrate the crucifixion on the fourteenth day of Nisan, which coincides with Pesach (or Passover) regardless of which day of the week upon this date falls, while the Roman Church celebrates the Pasch on Sunday—the weekday of Jesus' resurrection.

The two do not agree on a common date, but Anicetus concedes to Polycarp and the Church of Smyrna the ability to retain the date to which they are accustomed.

The controversy is to grow heated in the following centuries.

The Christian historian Hegesippus also visits Rome during Anicetus' pontificate.

This visit is often cited as a sign of the early importance of the Roman See.

Anicetus is the first Roman Bishop to condemn heresy by forbidding Montanism.

He also actively opposes the Gnostics and Marcionism.

According to Liber Pontificalis, Anicetus decreed that priests are not allowed to have long hair (perhaps because the Gnostics wore long hair).