The number of people who committed suicide from January through August came to 22,362, an increase of 4.5 percent from a year earlier, according to the National Police Agency.
If the pace continues, the annual figure could surpass the record 34,427 marked in 2003.
So far this year, 16,008 men and 6,354 women have taken their own lives. There have been year-on-year increases in every month since January.
In August alone, 2,497 people committed suicide, up 66 from a year earlier.
By prefecture, Saitama saw the largest increase, at 137, from the year before, followed by 114 in Chiba, 102 in Tokyo and 92 in Okinawa.
Suicides decreased by 50 in Hokkaido, 40 in Tottori and 32 in Nagano.
The government of Prime Minister Yukio Hatoyama has vowed to try to deal with the rise in suicides, which are believed to reflect worsening economic conditions since last fall.