Figures from the Scottish Qualifications Authority (SQA) showed a 9.6% decline in the number of French Higher pupils in 2013 compared to the previous year, down from 4688 to 4236.
The decline follows long-term trends in some modern languages, with numbers also falling in German.
However, this year the SQA figures showed an increase in candidates taking Higher Italian and Russian, and Spanish entries were up again after several years of increases.
Sarah Breslin, Scotland's National Centre for Languages director at Strathclyde University, called for a campaign raising awareness of the importance of French as a global language.
"French is still a popular language, but the decline at Higher is a bit worrying and we are also concerned there is a long-term decrease in the number of schools that are putting any candidates forward for Higher French," she said.
"We need to raise awareness among young people about the importance of French as a vital international language.
"French is the official language of important international bodies such as the OECD, the United Nations, Nato and the European Commission and there is currently a shortage of translators whose mother tongue is English.
"We are limiting the future employability of pupils and the representation from Scotland in these important organisations if we continue to see this decline."
Nathalie Korkmaz, director of the Alliance Francaise in Glasgow, which promotes the French language and culture, said parents were concerned about the drop.
"We do hear that schools have stopped offering French and there are also those families who say the amount of hours it is taught is not sufficient," she said.
The demise of languages in secondary has been blamed on the fact many schools no longer see them as compulsory, despite school inspectors calling for them to be a "core element" in the first three years of secondary.
In addition, as part of cuts to education budgets, two-thirds of local authorities have scrapped foreign language assistants, although some are now reinstating them.
There have also been problems in primary studies, with three-quarters of schools missing recommended targets for modern educational language delivery.
In May last year, a report by the Scottish Government's Languages Working Group said a decline in language learning at Scottish schools and universities was costing the economy at least half a billion pounds every year.
It said: "With fewer students taking languages to exam level ... this can impact on the viability of the language qualifications that the Scottish Qualifications Authority can offer and on higher education institutions maintaining their investment in language departments.
"This is resulting in fewer new teachers able to teach language skills and fewer linguists to satisfy the jobs market more generally."
The report pinned the blame on the previous Labour-led Scottish Government.
From 1989, an initiative called Languages for All had established compulsory language teaching up to S4, but this was swept away a decade later with a shift from compulsion to entitlement for secondary pupils.
A Scottish Government spokeswoman said: "Our ambitious languages policy to provide every child in Scotland with the opportunity to learn two languages in addition to their mother tongue by 2020 underlines our commitment to supporting a future workforce in a global economy.
"We have already invested an extra £4m to language learning for the forthcoming school year.
"We want all children to be able to benefit from the skills learning a language provides."