Factors influencing the neonatal therapeutic effect of anti-MRSA (methicillin-resistant Staphylococcus aureus) drugs are investigated.This study took place over a two-year period from April 1998 to March 2000. We calculated the non-adjusted odds ratio for each influential factor to determine the therapeutic effect of anti-MRSA drugs.Significant factors for therapeutic effect were found to be platelet count, urea nitrogen, creatinine, and CRP, each measured before starting administration of anti-MRSA drugs; whether blood drug concentration was measured; and whether pneumonia or septicemia was present. There was a tendency where a better therapeutic effect was gained when the total protein and albumin values were high. We applied multivariate logistic regression analysis to these factors, and found the following independent significant factors: CRP (odds ratio (OR) = 1.582), albumin (OR = 3.079), Cre (OR -0.213), whether blood drug concentration was measured (OR = 3.767), and presence of pneumonia or septicemia (OR = 0.216). This result suggests that consideration should be given to these five important factors when treating MRSA patients.