BACKGROUND: Parental incarceration (PI) is associated with mental and behavioral problems in offspring, but causality remains unclear. We conducted a quasi-experimental within-individual study on the associations of PI with offspring psychiatric disorders, suicidal behavior, risk-taking, and substance misuse events, aiming to test the effect of PI on offspring. METHODS: The study included 43,011 and 5,912 individuals born in Sweden 1973-2010 and exposed to paternal or maternal incarceration, respectively, between ages 10 and 30. Using data from nationwide registers available until the end of 2020, we examined associations between PI and offspring time-varying events in a longitudinal within-individual design to control for time-invariant confounding. We further studied potential moderation effects in within-individual models by offspring sex, family living arrangements, age, and other factors. For comparison, we conducted corresponding between-individual analyses. RESULTS: Overall, no clear within-individual associations between paternal or maternal incarceration and offspring events were observed (HRs 0.99-1.08 and 0.82-1.03, respectively), but in a sensitivity analysis, the first recorded exposure to PI was associated with a slightly increased risk of some events (HRs 1.08-1.10). Regarding moderation effects, preliminary evidence suggested that child-father coresiding, paternal offending type, and exposure age slightly moderated the within-individual associations for certain outcomes. Statistically significant associations were found in all between-individual models. CONCLUSIONS: The elevated rates of mental and behavioral problems among offspring exposed to PI are unlikely to be due to a direct impact of PI, but an impact may exist under certain circumstances. These findings can help in targeting support to this vulnerable group.