OBJECTIVE The purpose of this study was to quantify the intra- and postoperative complications of an interspinous process device (Coflex) in managing degenerative lumbar diseases and to investigate corresponding therapeutic strategies. METHODS Between January 2008 and December 2012, we retrospectively analysed a total of 131 patients who underwent decompressive surgery along with the Coflex system for the treatment of degenerative lumbar diseases. The related complications were reported, and appropriate measures were taken. Clinical outcomes and radiological data were collected and analysed, and clinical outcomes were evaluated with paired-samples T test. RESULTS Related complications occurred in 11 patients. Among them, six cases were found with surgical technique-related complications, including device-related complications in three cases: spinal process fracture (n = 1), Coflex loosening (n = 1), fixed-wing breakage (n = 1), dura mater tear in two cases and superficial wound infection in one case. All of them received corresponding conservative treatment and obtained a good result. The other five cases had non-device-related complications and required additional spinal surgery. The conservative therapy group had apparent improvement of VAS score and ODI, and remained well to final follow-up (P < 0.05). The second operation group also improved postoperatively (each P < 0.05). CONCLUSIONS The Coflex dynamic interspinous process device shows a low complication and re-operation rate. Standard operation and strict follow-up observation can effectively avoid surgical technique-related complications. The key points to ensure surgical effect and to reduce non-device-related complications are mastering surgical indications and thorough intra-operative decompression.