1978 Nations motorcycle Grand Prix

Date14 May 1978

Official nameGran Premio delle Nazioni^[1][2][3]

LocationAutodromo Internazionale del Mugello

Course

• Permanent racing facility
• 5.245 km (3.259 mi)

  1978 Nations Grand Prix

Race details
Race 5 of 13 races in the 1978 Grand Prix motorcycle racing season
Date	14 May 1978
Official name	Gran Premio delle Nazioni[1][2][3]
Location	Autodromo Internazionale del Mugello
Course	Permanent racing facility 5.245 km (3.259 mi)
500cc
Pole position Rider Kenny Roberts Time 2:05.600 Fastest lap Rider Kenny Roberts Time 2:04.800 Podium First Kenny Roberts Second Pat Hennen Third Marco Lucchinelli
350cc
Pole position Rider Franco Uncini Time 2:10.590 Fastest lap Rider Gregg Hansford Time 2:07.600 Podium First Kork Ballington Second Gregg Hansford Third Takazumi Katayama
250cc
Pole position Rider Kenny Roberts Time 2:11.360 Fastest lap Rider Kork Ballington Time 2:09.300 Podium First Kork Ballington Second Gregg Hansford Third Franco Uncini
125cc
Pole position Rider Eugenio Lazzarini Time 2:16.850 Fastest lap Rider Thierry Espié Time 2:15.100 Podium First Eugenio Lazzarini Second Maurizio Massimiani Third Harald Bartol
50cc
Pole position Rider Ricardo Tormo Time 2:30.330 Fastest lap Rider Stefan Dörflinger Time 2:28.000 Podium First Ricardo Tormo Second Patrick Plisson Third Julien van Zeebroeck
Sidecar (B2A)
Pole position Rider Alain Michel Time 2:13.490 Fastest lap Rider Rolf Biland Time 2:14.700 Podium First Rolf Biland Second Werner Schwärzel Third Jean-François Monnin

The 1978 Nations motorcycle Grand Prix was the fifth round of the 1978 Grand Prix motorcycle racing season. It took place on the weekend of 12–14 May 1978 at the Autodromo Internazionale del Mugello.