There is no report on the initial antiepileptic drug (AED) treatment of older Thai epileptic patients. This study aimed to determine the trends, prescribing patterns, and determinants of initial AED treatment. This cross-sectional study used data on older (≥60 years) epileptic patients gathered from one tertiary-care hospital's database from 2012 to 2022. We evaluated the trends and prescribing patterns for starting AED treatment. We used logistic regression to identify the determinants of the initial treatment with new-generation AEDs. This study comprised 919 participants (59.19% men, 70.99±8.00 years old). Between 2012 and 2022, we observed a decreasing trend in starting therapy with old-generation AEDs, from 89.16% to 64.58%. In contrast, there was an increasing trend in initiating treatment with new-generation AEDs, from 10.84% to 35.72% (P for trend <0.001 for both). Each assessment year, the most prescribed treatment pattern was monotherapy. The determinants of initial therapy with new-generation AEDs included the year treatment began (adjusted odds ratios [AOR] = 1.0006; 95% confidence intervals [CI] 1.0003-1.0008), non-Universal Coverage Scheme (AOR = 1.94; 95% CI 1.26-3.00), liver disease (AOR = 6.44; 95% CI 2.30-18.08), opioid use (AOR = 2.79; 95% CI 1.28-6.09), and statin use (AOR = 0.59; 95% CI 0.36-0.95). There is a growing trend of initiating treatment with new-generation AEDs in older Thai patients with epilepsy. Factors positively associated with starting new-generation AEDs include the year treatment began, non-Universal Coverage Scheme, liver disease, and opioid use, while statin use is a negatively associated factor.