1934 saw the return of Italy's prodigal son, Achille Varzi. Resulting from their on again off again relationship between Nuvolari and Ferrari it was Varzi driving a Scuderia Ferrari Alfa Romeo while his nemesis also in an Alfa, this time for the Scuderia Siena. This change of supporting casts would later affect the final results. Both drivers had the 8C 2300 Alfas at their disposal with Varzi's engine bored out to almost 2600 CC. To compensate Nuvolari's Jano prepared mount used the latest Memini carburetor with the result that both cars produced similar power.
This year the route was altered to include Mestre and Venice, crossing the long and recently completed bridge over the lagoon before passing through Treviso to Vicenza, from where the traditional route was again followed. The race was started at 4 a.m. under the threat of rain which had been heavily pouring all night. The early starting time would insure that the major part of the race would be held in daylight, such as there was. By 5:40 a.m. Nuvolari was off followed by Varzi 4 minutes later. Leading into Rome was the Alfa Romeo of Mario Tadini. Shortly there after he was passed by Varzi now in the lead followed by Nuvolari only seconds behind. By the time they reach Terni on the return leg to Brescia Varzi had opened up a lead of almost 3 minutes only to have it reduced to 20 seconds as they raced up the Adriatic coast.Tadini's race came to an end when his gear lever broke off and Chiron driving in his first Millie Miglia was promoted to a fantastic third. At Imola Varzi at the insistence of Enzo Ferrari changed to studded tires for added traction over the roads to come. The finishing order would stay the same as Varzi would win his first and only Mille Miglia.
Only eight minutes separated the arch rivals, Varzi and Nuvolari at the end of fourteen hours of hard racing. Had it not been for some poor tire choices and a botched fuel stop the tables might have been turned. The M.G. K3 Magnettes had the tables turned on them and were soundly trounced by the 4C 1100 Maseratis. Leading the Maseratis was Piero Taruffi who almost ran out of gas miles from their nearest depot. Because most of the leading cars used a gas-alcohol mixture a change to the carburetor's fuel jet was required if they were going to fill up on fuel from a local gas pump. Luckily for Taruffi his co-driver was one of Maserati's top mechanics, Guerrino Bertocchi and the pair went on to finish 5th overall.