That was worse than forecasts for a 1.0 percent decline, which would have matched August's rate. Core CPI was flat on month.
Overall CPI was down 0.6 percent on year and up 0.3 percent on month.
Core inflation in Tokyo - considered a leading indicator for the nationwide trend - was down 0.5 percent on year in October, and up 0.4 percent on month.
Tokyo's overall CPI was up 0.3 percent on year and up 0.5 percent on month.