About 150 Scandinavian, Dutch and German extremists exploited more liberal freedom of speech laws in neighbouring Denmark to rally in the town of Koege on Saturday. Many waved swastika flags, chanting "Sieg Heil" and "Hess - Fighter For Peace".
Neo-Nazis in Germany played cat-and-mouse with police, keeping their plans for gatherings secret in an attempt to beat widespread bans imposed on any events connected with Hess, who died on 17 August 1987, in Spandau prison, Berlin.
Police in the state of Thuringia said they had detained 94 people and also seized baseball bats, neo-Nazi music cassettes and propaganda material at special traffic checkpoints set up to intercept the extremists before they could gather.
Police in the northern state of Lower Saxony said they believed the main rally had been planned for somewhere in their area but they had managed to stop it going ahead, detaining around 160 people.
Sixty neo-Nazis were detained in Koenigslutter, northern Germany, after trying to rally outside the local cathedral.
Judges from Germany's highest court held a special late-night session on Saturday to block a last-minute attempt to hold a rally in the small Bavarian town where Hess is buried. The Federal Constitutional Court rejected a challenge to a ban on gatherings connected with Hess in the town of Wunsiedel.