Stress corrosion cracking (SCC) of C36000 brass, a multiphase copper-zinc alloy, in two ammoniacal environments -- aqueous and vapor -- was examined. Both caused a significant decrease in mechanical properties relative to the values measured on air. The effect of cold working the alloy was to increase the resistance to SCC. Mechanisms are given for the be-havior under constant load and constant strain tests. The crystallographic dependence of SCC in 70Cu-30Zn brass was investigated. -- AATA