Pelvic exenteration for locally advanced rectal cancer (LARC) and locally recurrent rectal cancer (LRRC) is technically challenging but increasingly performed in specialist centres. The aim of this study was to compare outcomes of exenteration over time. This was a multicentre retrospective study of patients who underwent exenteration for LARC and LRRC between 2004 and 2015. Surgical outcomes, including rate of bone resection, flap reconstruction, margin status and transfusion rates, were examined. Outcomes between higher- and lower-volume centres were also evaluated. Some 2472 patients underwent pelvic exenteration for LARC and LRRC across 26 institutions. For LARC, rates of bone resection or flap reconstruction increased from 2004 to 2015, from 3·5 to 12·8 per cent, and from 12·0 to 29·4 per cent respectively. Fewer units of intraoperative blood were transfused over this interval (median 4 to 2 units; P = 0·040). Subgroup analysis showed that bone resection and flap reconstruction rates increased in lower- and higher-volume centres. R0 resection rates significantly increased in low-volume centres but not in high-volume centres over time (low-volume: from 62·5 to 80·0 per cent, P = 0·001; high-volume: from 83·5 to 88·4 per cent, P = 0·660). For LRRC, no significant trends over time were observed for bone resection or flap reconstruction rates. The median number of units of intraoperative blood transfused decreased from 5 to 2·5 units (P < 0·001). R0 resection rates did not increase in either low-volume (from 51·7 to 60·4 per cent; P = 0·610) or higher-volume (from 48·6 to 65·5 per cent; P = 0·100) centres. No significant differences in length of hospital stay, 30-day complication, reintervention or mortality rates were observed over time. Radical resection, bone resection and flap reconstruction rates were performed more frequently over time, while transfusion requirements decreased.