This updated standard, Design of Latticed Steel Transmission Structures (ASCE 10-97), provides requirements for the design of guyed and self-supporting latticed steel electrical transmission structures. They are applicable for hot-rolled and cold-formed steel shapes. Analysis techniques are outlined for the geometrical configurations presently in use. Procedures for the design of individual members reflect extensive experience and test data on steels with yield points up to 65 ksi. Connection design procedures allow the engineer to match connection capability to the most suitable end and edge distances for detailing. If full scale structure testing is required procedures are outlined to assist in obtaining critical information. Design procedures cover structural steel members and connections used in foundations. The commentary provides supporting background data.