The cold workability of solution-treated TiNbZr biomedical β titanium alloy was investigated. TiNbZr alloy was fabricated by vacuum consumable arc melting furnace. Cold drawing was carried out for further deformation of the studied alloy. During cold drawing, the alloy exhibited excellent workability. Deformation twins appeared when the reduction of cold deformation was around 20%. Dislocations slipping contributed much to plastic deformation in further drawing. The ultimate tensile strength will go up to 1170 MPa and the elongation is larger than 10% when the reduction reaches 80%. Small grains ranging from 20 nm to 50 nm can be obtained when the reduction is 80%.