Egypt's tourism revenue plunged by 24.7% to around $3bn (£1.8bn, €2.2bn) for the first half of the year, the country's tourism ministry said in a statement.
Tourists have largely stayed away from Egypt since former president Hosni Mubarak was ousted in 2011, sparking three-and-a-half years of political, social and economic turmoil.
The number of tourists who visited Egypt in the first six months of 2014 reached 4.5 million, down 25% on the numbers from the same period last year.
Tourism is the country's biggest source of foreign currency revenue and the dismal returns seen in the first half of the year will be a concern for the country's third president in as many years.
Abdel Fattah al-Sisi, a former head of the armed forces, secured the presidency with a landslide election victory in June.
Sisi promised to usher in a new period of stability in the Arab world's most populous nation but his months in office have been marked by sporadic political violence in the Sinai peninsula and sometimes in Cairo.
For the most part, violence has been directed at state security forces and the army but tourists have occasionally been targeted in the past.
Moreover, three South Korean tourists were killed in February this year after a bus they were travelling on was bombed. An al-Qaeda-affiliated group later claimed responsibility for the attack.
In 2010, the year before the uprising centred in Cairo's Tahrir Square that toppled Hosni Mubarak, 14 million tourists had visited the country. The revenues from the industry made up 14% of Egypt's gross domestic product.
However, those numbers have been on a downward trajectory ever since, with fewer and fewer tourists visiting during a tumultuous few years.