SBS's hit drama Doctor X: The Age of the White Mafia, starring Kim Ji Won, continues to impress viewers as it reaches another personal best in ratings.

According to reports on October 18, the drama's fourth episode, which aired on October 17, recorded an impressive 18.5% nationwide rating and a peak rating of 20.8%, setting a new record for the series.

The episode also earned an 18.4% rating in the Seoul metropolitan area, showing the drama's growing popularity among viewers.

With these results, Doctor X ranked No. 1 in its time slot, among Saturday miniseries, and among all weekly miniseries. The drama has continued to break its own viewership records with each new episode.

The series also performed strongly among viewers aged 20 to 49, a key demographic for television advertisers. Episode 4 recorded an average rating of 5.9% and a peak of 6.56% in this category, ranking No. 1 among all programs broadcast on Saturday.

The latest episode followed Kim Ji Won's character, Gye Soo Jung, as she continued to face challenges at Guseo University Hospital. Tensions increased following the arrival of a new surgeon, Na Dae Il, played by Jang Seung Jo, whose unusual interest in Soo Jung raised questions about his intentions.

The episode also highlighted Soo Jung's exceptional surgical abilities and her determination to protect patients despite growing conflicts within the hospital. Its suspenseful developments helped maintain viewers' interest without slowing down the story.

With nationwide ratings already reaching 18.5% and peak viewership surpassing 20%, Doctor X is now approaching the major milestone of a 20% nationwide average rating.

As the drama continues to achieve new personal bests with every episode, attention is growing over whether Kim Ji Won's latest series can maintain its momentum and reach even higher ratings in the coming weeks.