Objective: This study aimed to assess the levels of carbon monoxide (CO) in the air inside water-pipe cafés in Karachi, Pakistan. Methodology: During June 2015, three water-pipe cafés in the city of Karachi, Pakistan were selected through convenience sampling. CO air samples were collected from the selected cafés using Carbon Monoxide USB Data logger. The graphs were automatically generated through the USB Data logger and the collected data was analyzed using Microsoft Excel. Results: The results showed that the overall readings of CO levels were within/lower than threshold limit value (TLV) of 25 ppm. However, there was an increase of CO levels in indoor air of all included water-pipe café during peak hours when the cafés were open and had a regular customer flow compared to the CO levels overnight. Conclusion: The findings of this study provide evidence that the air quality in water-pipe cafés is potentially hazardous to the health of its employees, which is critical to inform tobacco control policies and regulations for such venues. The study findings also indicate a clear need to extend research to not only focus on the indoor air quality of water-pipe cafés, but also the biological monitoring of employees in water-pipe cafés.