Purpose: This study investigated the activity of express extracts of Costus afer (bush-cane) against Escherichia coli, Staphylococcus aureus, Bacillus subtilis and Pseudomonas aerugionsa. Materials and Methods: The leave and stem sap of Costus afer was obtained from Wilberforce Island, Bayelsa state, Nigeria. The various plant parts (leave and stem) were separately macerated and the resultant extracts was obtained through filter-pressing using a double muslin cloth. The agar well diffusion method was employed for the sensitivity study. Results: The zone of inhibition exhibited by Escherichia coli, Staphylococcus aureus, Bacillus subtilis and Pseudomonas aeruginosa were 10.67±1.29mm, 11.67±0.88mm, 12.67±0.33mm and 9.00±0.58mm, respectively (for synergy), 10.00±1.56mm, 11.33±1.33mm, 12.67±0.88mm and 8.66±0.66mm, respectively (for stem extract), 9.33±0.33mm, 10.00±0.58mm, 9.67±0.33mm and 7.33 ±0.33mm, respectively. Analysis of variance showed that there were no significant variations (p>0.05) among the various isolates for each of the plant parts and their combination except for the leaves. Between the various plant parts for each of the test organisms, there was no significant variation (p>0.05) except for Bacillus subtilis. Conclusion: The inhibition by the stem and leave express extracts of Costus afer suggests that they possess broad-spectrum antibiotics potentials.