OBJECTIVE Systematic review of literature to evaluate safety of intracoronary (i.c.) pharmacologic testing with acetylcholine (ACh), or ergonovine (ERGO), to induce coronary artery spasm. RESULTS Review of all relevant publications using MEDLINE and EMBASE databases yielded 10 publications, totalling 9,444 patients. Prevalence of provoked spasm varied from 2.3% to 54.7% of patients tested in the selected studies. The wide variability in prevalence was due to heterogeneity of study populations and provocation protocols. No deaths were reported. Overall occurrence of major (0.8%) and minor (4.7%) complications for i.c. pharmacologic testing was low. Compared to ERGO, ACh showed significantly higher rate of major (1.09% vs 0.15%; p<0.001) and minor complications (5.87% vs 2.36%; p<0.001). CONCLUSIONS Provocative testing with i.c. ACh or ERGO are safe and can facilitate the diagnosis of inducible coronary artery spasm during diagnostic coronary angiography. These tests should be part of the routine armamentarium of interventional cardiologists.