This study aimed to investigate suicide and general mortality in individuals with gambling disorder and to evaluate the effect of gambling disorder on mortality and death from suicide. This is a Swedish nationwide case-control, register based study with a ratio of 1:2. Controls were matched on gender, age and municipality. Cases were defined as all adults with a diagnosis of gambling disorder in Swedish in-patient and/or specialized out-patient health care 2005-2019. The total population included 10,782 individuals. Multifactor Cox regression stratified for sex was used to analyze risk factors for suicide mortality and general mortality. Suicide mortality was higher amongst cases, with 41 (1.2%) individuals passing away due to suicide vs. 22 (0.3%) of the controls (p < 0.001). In the regression model, gambling disorder was not significantly associated with suicide mortality, which was associated with substance use disorder and low education in men and for women the model could not draw conclusions on predicting factors. Mortality was also elevated in cases; 94 of the deceased were controls (1.3%) and 132 were cases (3.8%, p < 0.001). In the regression model gambling disorder was not significantly associated with mortality, this was predicted by socioeconomic status, increasing age, low education level, somatic comorbidity, substance use disorder and previous intentional self-harm in men and for women by increasing age and somatic comorbidity. In conclusion, gambling disorder is associated with increased mortality and suicide death. Comorbid disorders and socioeconomic status appear to be important reasons for the increased mortality.