According to Official Guinness Records,
The world record for the most horses pulling a carriage is 141, in an event organised by 'le Comité des fêtes de Beaudinard et l’Association des 1000 ans' at Aubagne, France on 18 December 2005.
In total, 141 horses measured a length of 409,70 m (1344 ft 16 in) and pulled the carriage through the streets of Aubagne over a distance of 1500 m (4921 ft 25 in). Aubagne, a south-east of France town was this year celebrating its millennium. Festivities with horses are traditional in Provence.
For a complete list of 2005 records, please visit 2005 Guinness Records in France.