Background – The reliability of homeopathic prescriptions may increase through resource to objective signs and guiding symptoms with significant positive likelihood ratio (LR). We estimated LR for six objective signs attributed to the homeopathic medicine Natrum muriaticum (Nat-m). Methods – In this multi-centre observational assessment, we investigated the prevalence of six signs in the general patient population and among good responders to Nat-m in daily homeopathic practice. Next, we calculated LR for these six signs. Results – Data from 36 good responders to Nat-m and 836 general population patients were compared. We found statistically significant positive LR (95% confidence interval) for signs such as lip cracks (1.94; 1.15 to 3.24), recurrent herpes (2.29; 1.20 to 4.37), hairline eruptions (2.07; 1.03 to 4.18), and dry hands (2.13; 1.23 to 3.69). Conclusions – Objective signs with significant positive LR might increase the reliability of homeopathic prescriptions. Further studies are warranted to confirm the validity of this approach.