No, one's potential landlord or existing landlord cannot force a tenant to take a drug test as a condition of obtaining a lease or keeping the lease. Potential employers of an employee can make a condition of employment in a written agreement or policy manual required drug testing, but not in a landord tenant situation.However, if a potential landlord requests a drug test as part of the application process to a potential tenant, he or she can agree to the testing or refuse. However, if there is a refusal of a requested drug test by the landlord from the applicant for a rental, the chances of being offered the unit will most likely be substantially reduced.