The aim of this study was to investigate the prevalence of benzodiazepine and related drug (BZDR) use, especially long-term use, and associated factors among community-dwelling individuals with and without Alzheimer's disease (AD). We utilized data from the MEDALZ-2005 cohort, which includes all community-dwelling individuals diagnosed with AD in Finland at the end of 2005 and matched comparison individuals without AD. Register-based data included prescription drug purchases, comorbidities, and hospital discharge diagnoses. In this study, 24,966 individuals with AD and 24,985 individuals without AD were included. During the 4-year follow-up, we found that 45% (N = 11,312) of individuals with AD and 38% (N = 9534) of individuals without AD used BZDRs. The prevalence of long-term (≥ 180 days) BZDR use was more common among individuals with AD (30%) than individuals without AD (26%). The median durations of the first long-term use periods of BZDRs were 1.5 and 2 years for individuals with and without AD, respectively. Factors associated with long-term BZDR use included female sex, AD, schizophrenia, bipolar disorder, depression, coronary artery disease, and asthma/chronic obstructive pulmonary disease. The high prevalence of long-term BZDR use among individuals with AD is especially a cause for concern because long-term use may further impair cognition and may be associated with serious adverse events.