OBJECTIVES The question of sequencing multiple myeloma (MM) treatments is a key one, as is the retreatment in patients where the same treatment was effective in earlier lines. We investigated bortezomib retreatment in a Swedish MM national registry. METHODS Patients diagnosed with MM since January 2000 until June 2011 from 7 university clinics, 5 regional centers and 3 local hospitals in Sweden were included. Time to response and overall survival (OS) were analyzed using stratified Kaplan-Meier analysis. RESULTS Of the 541 patients treated with bortezomib (out of a total population of n=1638), 93 were retreated with bortezomib. Median follow-up from start of retreatment was 10.2 mos. Median age was 63.5 (range 38–83), 57.3% were male, 34.2%/15.9%/20.7% had stage I/II/III disease (ISS) ; median number of prior therapies at initial bortezomib and retreatment was 1 and 3. 26.8%/32.9% of pts initiated retreatment as 3rd/4th line therapy. 37.8%/22.0% initiated bortezomib retreatment in combination with dexamethasone, 7.3% in monotherapy, compared to 40.3%, 21.8% and 8.5%, at initial bortezomib. ≥PR/VGPR-rates at re-treatment were 59.1%/12.7%, compared to 82.0%/39.9% at initial bortezomib. Median time to ≥PR/VGPR was 2.4/1.3 months at retreatment versus 1.9/2.1 at initial bortezomib. The ≥PR rate at retreatment was numerically longer in patients with <=2 (75.1%) vs >=3 (20%) therapies prior to retreatment. Median PFS/OS from start of re-treatment was 5.5 [95%CI:3.7,10.0]/17.4 [10.3,26] months, compared to 8.1 [6.9,9.7]/25.9 months [21.0,31.6] for initial bortezomib. Number of prior therapies at retreatment did not affect PFS; however, OS was longer in pts with fewer prior therapies (p=0.0112). There was a trend towards longer PFS (p=0.087) in retreated patients who achieved >=PR compared to non-responders. CONCLUSIONS These data suggest that, in everyday medical practice, bortezomib retreatment is effective in relapsed/refractory MM, with more than half of pts who responded to initial bortezomib achieving ≥PR at retreatment.