The rule of the Targa, known some months before the race, fixed the formalities for the entrance, for the participation and the qualification of enrolled racing cars. At the beginning, each constructor firm could enroll 4 cars. Private citizen could enter the race when that number was not attained. As years went by, the rules changed: for example, in 1919, the number of enrolled cars (for each firm) was unlimited. Moreover, an admission fee, the pilots’ weight and, later, different categories for the cars were fixed. The dead-line for the entries was 7 days before the race.
Before starting the race, the competition commissioners in person disassembled and examined the cylinders of the engines, in order to check that there weren’t differences from what the constructors had declared before. In case of difference, the car was not left out of the competition, but it was included in the corresponding category, according to the number of cylinders.
It was fixed that, for each car, the two competitors’ minimum weight should be 120 Kg.
The starting- order was decided in drawing of lots. Then the enrolled cars were divided according to the cylinders. After this, some cans were drawn. Inside these cans there were the names of the enrolled cars: the constructor firms decided which pilot should be the first one of starting. After the division in categories, the cars of the first category started and so on. Therefore the draw were done about the enrolled pilots.

The distance between each car was fixed in accordance with the enrolled competitors’ number. Afterwards, it was standardized a distance of one minute.
Two pilots could alternate during driving. This exchange could be done at the end of each lap. The pilots chosen for the driving could not be replaced during the race.
At first, the car refuellings were done in the pits. Then it was possible to refuel also along the circuit.
The prizes were awarded the first 4 or 5 pilots who had breasted the tape. They consisted of an amount of money and various medals. Who had came in first received the Targa Florio. In addition to the pilots, each mechanician was given a medal.
Sometimes, the organizers decided a free transport for the enrolled cars, from the harbors of Marseilles, Genoa, Venice and Palermo. Each taken aboard car could be accompanied by two people, who were taken aboard free, too.