During the 1970s the club had a relatively successful spell when they were considered one of the best sides in the county, winning the Cornwall Cup twice as well as finishing top of the Cornwall Merit Table in 1977. When league rugby was introduced in 1987, Falmouth were placed in the Cornwall/Devon League, at tier 8 of the English rugby union system. Following the club's relegation at the end of the 1989–90 season they spent much of the next decade playing in Cornwall League 1. A second promotion from Cornwall League 1 early on in the 21st century, saw Falmouth consolidate its position in the Cornwall/Devon League, with fourteen uninterrupted seasons in tier 8. At the end of the 2017–18 season Falmouth won the Cornwall/Devon league title and with it promotion to Western Counties West, the highest level the club had reached so far.
Green background stands for either league champions (with promotion) or cup winners. Blue background stands for promotion without winning league or losing cup finalists. Pink background stands for relegation.
^There was no relegation from Cornwall/Devon at the end of 2008–09 season, which meant Falmouth were saved from relegation despite finishing bottom of the table.
^The 2010–11 season would see the introduction of bonus points into lower league English rugby union (tier 6 and below).
^The season was postponed and ultimately cancelled due to the COVID-19 pandemic in the United Kingdom with Falmouth sitting in 8th, having played 22 games and gained 37 points. The remaining games were calculated on a 'best playing record formula', with Falmouth remaining in 10th place with 43.73 points.[52]