Jelcz PR100 is a Polish, medium-floor city bus, which was presented for the first time in 1972. Its serial production was carried out in the years 1972-1975 and took place in Zakłady Samochodowe Jelcz. The Jelcz PR100 was developed as a successor to the Jelcz 272 MEX city bus, often popularly called a cucumber, being the result of cooperation between the Jelcz plant and the French company Berliet. Compared to its predecessor, it was a completely new structure, which differed in a very significant way on almost every level. First of all, the Jelcz PR100 was not based on a truck chassis, but from the very beginning was designed as a city bus, which allowed, for example, to place the engine compartment at the rear of the vehicle. An all-new 170 HP Berliet V800 engine was also used. A completely different body, much more glazed, was also used. At the time of putting into production, the Jelcz PR100 turned out to be a very modern vehicle, but it showed many shortcomings - first of all it was highly emergency, it had insufficient passenger compartment capacity, and it had only two pairs of doors. For these reasons, it was relatively quickly replaced by a more successful design - the Jelcz PR110.