Objective: To investigate falls and risk factors in patients with myotonic dystrophy type 1 (DM1) compared with healthy volunteers. Methods: 13 sequential patients with DM1 from different kindreds were compared with 12 healthy volunteers. All subjects were evaluated using the Rivermead Mobility Index, Performance Oriented Mobility Assessment, and modified Activities Specific Balance Confidence scale. Measures of lower limb muscle strength, gait speed, and 7-day ambulatory activity monitoring were recorded. Subjects returned a weekly card detailing stumbles and falls. Results: 11 of 13 patients (mean age 46.5 years, seven female) had 127 stumbles and 34 falls over the 13 weeks, compared with 10 of 12 healthy subjects (34.4 years, seven female) who had 26 stumbles and three falls. Patients were less active than healthy subjects but had more falls and stumbles per 500 0 right steps taken (mean (SD) events, 0.21 (0.29) v 0.02 (0.02), p = 0.007). Pa tients who fell (n = 6) had on average a lower Rivermead Mobility score, slower self selected gait speed, and higher depression scores than those who did not. C onclusions: DM1 patients stumble or fall about 10 times more often than healthy volunteers. Routine inquiry about falls and stumbles is justified. A study of mu ltidisciplinary intervention to reduce the risk of falls seems warranted. Objective: To investigate falls and risk factors in patients with myotonic dystrophy type 1 (DM1) compared with healthy volunteers. Methods: 13 sequential patients with DM1 from different kindreds were compared with 12 healthy volunteers. All subjects were evaluated using the Rivermead Mobility Index, Measures of lower limb muscle strength, gait speed, and 7-day ambulatory activity monitoring were recorded. Results: 11 of 13 patients ( mean age 46.5 years, seven female) had 127 stumbles and 34 falls over the 13 weeks, compared with 10 of 12 healthy subjects (34.4 years, seven female) who had 26 stumbles and three falls. Patients were less active than healthy subjects but had more falls and stumbles per 500 0 right steps taken (mean SD events, 0.21 (0.29) v 0.02 (0.02), p = 0.007). Pa tients who fell (n = 6) had on average a lower Rivermead Mobility score, slower self selected gait speed, and higher depression scores than those who did not. C onclusions: DM1 patients stumble or fall about 10 times more often than healthy volunteers. mu ltidisciplinary intervention to reduce the risk of may seem warranted.