This study evaluates the effectiveness of the "Seoul Sanitation Grading System Evaluation Index" developed earlier and to analyze sanitation management practices in restaurants in Seoul, Korea. The categories evaluated were the food management standard, facilities/equipment standard, and essential checking items specified in the law. These items were graded and classified into A ($100{sim}90$), B ($89{sim}80$), C ($79{sim}70$) and Score (less than 69) based on the criteria set by the present researchers. We randomly selected 56 restaurants in five local cities (Jung-gu, Seocho-gu, Jongno-gu, Songpa-gu and Yeongdeungpo-gu) and investigated each by actually visiting the site of business. The achievement rate for food management standard was 80.8%; as for the specific items in the category, it was the highest in food ingredients at 77.1% and the lowest in food storage at 62.1%. For the facilities/equipment standard, the achievement rate was 77.8%; as for the specific items in the category, it was the highest for vermin at 88.1% and the lowest for operation at 70.8%. The achievement rate for overall individual sanitary management was 70.7% and in the category, the lowest score was seen in hand washing at 57.1%. The overall average score of sanitation management practices using the Seoul Sanitation Grading System Evaluation Index in restaurants in Seoul was 73.7, which fell into the C category. As for the number of restaurants in each grade category, there were 10 (17.9%) in each category of A ($100{sim}90$), B ($89{sim}80$) and C ($79{sim}70$) with 30 (53.6%) scoring higher than 70, whereas those scoring less than 69 included 26 (46.4%). The average scores for those restaurants designated by local governments (exemplary restaurants, general restaurants, best Korean restaurants in Seoul) were not significantly different; however, they were higher in franchises than those small restaurants ran by individuals.