©　2017,　American　Society　of　Interventional　Pain　Physicians.　All　rights　reserved.　Background:　Although　percutaneous　kyphoplasty　(PKP)　could　achieve　rapid　pain　relief　for　the　elderly　with　osteoporotic　vertebral　compression　fracture　(OVCF),　some　patients　still　had　risks　of　suffering　vertebrae　delayed　union　which　led　to　persisting　pain　and　vertebral　collapse.　Preventing　the　delayed　vertebral　union　could　reduce　the　further　morbidities　and　medical　costs　for　patients　with　OVCF　after　PKP.　Objectives:　To　explore　the　factors　involved　in　delayed　vertebral　union　after　PKP　in　patients　with　OVCF.　Study　Design:　Retrospective　analysis.　Setting:　All　data　were　from　Hong-Hui　hospital　in　Xi’an.　Methods:　There　were　580　patients　treated　using　single-segment　PKP　between　January　2011　and　January　2012.　Demographics,　clinical　data,　types　of　vertebral　fracture,　and　surgical　data　were　collected　to　analyze　the　factors　associated　with　delayed　vertebral　union　after　PKP.　Results:　Twenty-nine　patients　(5%)　experienced　delayed　vertebral　union.　Univariate　analyses　showed　that　preoperative　bone　mineral　density　(BMD),　cement　consumption,　intravertebral　cleft,　restoration　rate　of　vertebral　height,　and　improvement　in　kyphotic　angle　were　associated　with　delayed　union　of　vertebrae　after　PKP　(P　＜　0.05).　Multivariate　analysis　revealed　that　preoperative　BMD　(odds　ratio　(OR)　=　0.452,　95%　confidence　interval　(CI):　0.207　–　0.987,　P　=　0.046),　intravertebral　cleft　(OR　=　9.156,　95%　CI:　3.712　–　22.585,　P　＜　0.001),　and　restoration　rate　of　vertebral　height　(OR　=　2.731,　95%　CI:　1.622　–　4.599,　P　＜　0.001)　were　independently　associated　with　delayed　union　of　vertebrae.　Limitation:　A　multi-center　study　is　recommended　to　confirm　our　findings　and　explore　the　factors　related　to　vertebrae　delayed　union.　Conclusions:　Preoperative　BMD,　intravertebral　cleft,　and　restoration　rate　of　vertebral　height　could　be　factors　independently　associated　with　delayed　union　of　vertebrae　after　PKP　in　patients　with　OVCF.