A total of fourteen teams were invited to participate in the 1974 Giro d'Italia. Each team sent a squad of ten riders, which meant that the race started with a peloton of 140 cyclists. Three riders from Rokado did not start the race after enrolling, which reduced the starting field to 137. From the riders that began this edition, 96 made it to the finish Milan.
Reigning champion and four-time winner Eddy Merckx returned to the race in 1974 to defend his crown. Merckx came into the Giro d'Italia after not having won a single spring classic for the first time since 1965. According to author Bill McGann, José Manuel Fuente entered the Giro in good form after winning the Vuelta a España weeks earlier.l'Unita interviewed several of the riders and many named Merckx as the favorite to take the victory. Gino Sala named Baronchelli, Battaglin, and Moser as three young riders who have the potential to become stars during the race.
The route for the 1974 edition of the Giro d'Italia was revealed to the public by race director Vincenzo Torriani on 29 March 1974. It contained one were individual time trial. There were eleven stages containing twenty three categorized climbs, of which four had summit finishes: stage 11a, to Il Cioccio; stage 16, to Monte Generoso; stage 18, to Borgo Valsugana; and stage 20, to Tre Cime di Lavaredo. In total the race route contained 26.78 km (17 mi) of official climbing across the twenty-three climbs. The organizers chose to include two rest days, in Capri and Sanremo. When compared to the previous year's race, the race was 200 km (124 mi) longer, lacked a prologue, and had the same number of rest days and individual time trials. In addition, this race contained two more stages, as well as one more set of half stages.
Upon the release of the route in March, La Stampa writer Gianni Pignata believed that the first leg of the split eleventh stage, to Il Cioccio, along with stages 20 and 21, which featured eight total climbs in the Dolomites, would be decisive in determining the race's winner. Pignata believed this edition of the Giro d'Italia was geared towards climbers. After looking over the race route, Italian rider Marino Basso stated that there were few opportunities for sprinters to try and win a stage. Two-time winner Felice Gimondi felt the race started off hard and agreed with Pignata and Basso, in that the race favored climbers and lacked chances for sprint finishes. He stated that the route suited the riding styles of Luis Ocaña, Eddy Merckx, and José Manuel Fuente. In addition, Gimondi criticized Torriani for placing a rest day in after the third day of racing, stating that there was no justification for it there.
Three different jerseys were worn during the 1974 Giro d'Italia. The leader of the general classification – calculated by adding the stage finish times of each rider, and allowing time bonuses for the first three finishers on mass-start stages – wore a pink jersey. This classification is the most important of the race, and its winner is considered as the winner of the Giro.
For the points classification, which awarded a purple (or cyclamen) jersey to its leader, cyclists were given points for finishing a stage in the top 15; additional points could also be won in intermediate sprints. The green jersey was awarded to the mountains classification leader. In this ranking, points were won by reaching the summit of a climb ahead of other cyclists. Each climb was ranked as either first, second or third category, with more points available for higher category climbs. The Cima Coppi, the race's highest point of elevation, awarded more points than the other first category climbs. The Cima Coppi for this Giro was the Tre Cime di Lavaredo. The first rider to cross the Tre Cime di Lavaredo was Spanish rider José Manuel Fuente.
Although no jersey was awarded, there was also one classification for the teams, in which the awarded points to each team based off their riding's finishing position in every stage; the leading team was the one with the most points.
The rows in the following table correspond to the jerseys awarded after that stage was run.