Universal Touring Company

Address: al-Tahrir Square, Sana'a
Phone: +967 1 272861/ 2 / 3
Fax: +967 1 275134
Email: touring@utcyemen.com
Website: www.utcyemen.com
The most reliable in terms of quality of service and level of security. A bit on the expensive side though, but this should not be a concern for western travelers.