Endometrial hyperplasia is caused by an excess of estrogen unopposed by progesterone. Oral progestogens are traditionally used for endometrial hyperplasia without atypia. However oral progestogen is not always successful at causing regression of endometrial hyperplasia. In addition, cyclic progestogens are less effective in delivering progestogen to the endometrium. Therefore, the levonorgestrel-intrauterine device (LNG-IUD), as an alternative option of delivery progestogen has been introduced in clinical practice. The effectiveness of LNG-IUD in causing regression of endometrial hyperplasia in the short-term had moderate-quality evidence, but the long-term (13 months to two years) effectiveness had low-quality evidence. In this study with relatively large sample size, we compared the effectiveness in the regression of endometrial hyperplasia without atypia for short-term and long-term between the treatment with LNG-IUD and oral progestogens or no treatment. Data on histology or ultrasound from 466 cases who received either LNG-IUD or oral progestogens or were untreated were collected. The primary treatment with LNG-IUD showed a 93% regression rate of endometrial hyperplasia, which was significantly higher than oral progestogens showing a 66% regression rate. The odds ratio of regression of endometrial hyperplasia in cases with LNG-IUD treatment was 7.128 (95%CI: 2.94, 16.76, p < 0.0001), compared to the cases with oral progestogen treatment. The regression rate in untreated cases was 16%. In addition, cases without regression by oral progestogens who then received the alternative treatment option by LNG-IUD also showed a 93% regression rate. While continuously receiving oral progestogens showed a 55% regression rate of endometrial hyperplasia, which was significantly lower than LNG-IUD treatment as an alternative option. Our data reports a significant response on regression of endometrial hyperplasia after LNG-IUD treatment in comparison with oral progestogen treatment.