OBJECTIVES:  Although there are a number of treatments available for patients with multiple myeloma (MM), a “watchful waiting” approach can often be used among patients who are asymptomatic. This study sought to understand the frequency of “watchful waiting” across regions and identify the strongest predictors of this strategy. METHODS: A retrospective chart review of patients with MM was conducted by physicians in the United States (N=6,085) and 5EU (France, Germany, Italy, Spain, UK; N=4,379) between Q4 2015 and Q3 2016. Physicians randomly selected patient charts and abstracted data on patient demographics and disease and treatment history. Only patients with complete watchful waiting information were included. Regression models predicted watchful waiting and time spent waiting from available patient and physician variables. RESULTS:  A total of 8,798 patients were included (mean age =68.7 years [SD=9.4], 58.2% male). "Watchful waiting" was significantly more common in the 5EU (11.4%) than in the US (5.4%) (p<.05). The strongest predictors of engaging in a "watchful waiting" period was being in Spain ((odds ratio [OR] = 9.63), being in Germany (OR = 9.40), being treated by an internist (OR = 4.43), being male (OR = 1.19), having a low risk stratification (OR = 1.21), being older (OR = 1.02), and being a non-smoker (OR = 1.51) (all p<.05). Similar factors were associated with length of watchful waiting (mean = 20.5 months, median = 12.0 months). However, although being treated by a hematologist or hematologist/oncologist were not associated with an increased likelihood of "watchful waiting" they were both associated with a longer period if it did occur (bs = 1.32 and 0.55, respectively; ps<.05). CONCLUSIONS: "Watchful waiting" was relatively uncommon in the study sample, though more common in Western Europe than in the US. Specific countries, notably Germany and Spain, were the strongest predictors though other physician and patient level factors contributed.