(Objective) The volcanic activities of Mt. Sakurajima releases various air pollutants. For example, volcanic ash from Mt. Sakurajima contains up to 7 wt. % of cristobalite. Outdoor radon levels were also reported to be relatively high in the area near the volcano. The present study examined the association of chronic respiratory disease mortality with the volcanic activities of Mt. Sakurajima in Kagoshima Prefecture, Japan. (Methods) Standardized mortality ratios (SMRs) and their 95% confidence intervals (95% CIs) during the period 1965-2006 were calculated, using the entire Kagoshima Prefecture as the reference population. In addition, the relative risks (RRs) and their 95% CIs among residents aged 50-84 years in Tarumizu and in eight other cities with similar population sizes in Kagoshima Prefecture for the period 1975-1995 were calculated, using Poisson regression analysis of grouped data. The frequency of explosions, the amount of ashfall, and the outdoor concentrations of SPM and SO2 were obtained from local authorities. (Results) The volcanic activities of Mt. Sakurajima has been most active in the 1980s in the second half of the 20th century or later. The SMRs of lung cancer for males and females in Tarumizu for the period between 1965 and 2006 were 1.61 (95% CI: 1.44-1.78) and 1.68 (95% CI: 1.40-1.97), respectively. No evident time trend was observed. The SMRs of all respiratory diseases other than cancer for males and females for the period between 1965 and 2006 were 1.38 (95% CI: 1.28-1.48) and 1.21 (95% CI: 1.11-1.31), respectively. The SMRs showed a peak in the period of 2003-2006. The SMRs of COPDs for males and females for the period of 2003-2006 were 2.75 (95% CI: 1.81-3.69) and 1.90 (95% CI: 0.72-3.08), respectively. The RRs of lung cancer mortality among residents in Tarumizu, compared with those in other cities, was 1.18 (95% CI: 1.01-1.39) for males and 1.35 (95% CI: 1.03-1.76) for females. The RR of all non-malignant respiratory disease mortality in Tarumizu with those in other cities was 1.16 (95%CI=1.03-1.30) for males and 0.92 (95%CI=0.78-1.08) for females; When men and women were combined, all non-malignant respiratory disease mortality in Tarumizu was not elevated. The RR of pneumoconioses in Tarumizu was relatively high only among men but not among women. The continuous measurement of outdoor radon concentrations, conducted by our study group in the 2000s, showed relatively high outdoor radon concentrations, exceeding 20 Bqm^{-3} in the study areas even though the volcano was not very active at the time of radon assay. (Conclusions) The present study showed that residents in Tarumizu, located near Mt. Sakurajima, experienced relatively high mortality rates of lung cancer. The mortality of COPDs and pneumoconioses may also be increased. It is suspected that cristobalite contained in the asfall of the volcano increases the mortality of those respiratory diseases. Further studies on the health effects of Mt. Sakurajima's volcanic activities seem warranted.