Aims: English national guidelines recommend that breast reconstruction is made available to women with breast cancer undergoing mastectomy. We examined the use of immediate reconstruction (IR) across English Cancer Networks, who are responsible for the regional organisation of cancer services and ensuring equitable access to treatment. Methods: We analysed Hospital Episodes Statistics data for all women with breast cancer who underwent mastectomy in the English NHS between April 2006 and February 2009. IR rates were calculated for the 30 Networks. Multivariable logistic regression was used to adjust the rates for patient age, comorbidity, ethnicity and socioeconomic deprivation. Results: Of 44 837 mastectomy patients, 7375 (16.5%) underwent IR. The IR rate was highest in women under 50 years (32.7%) and lowest in women aged 70 years or over (1.5%), and was lower in women with more comorbidities. Unadjusted IR rates varied from 8.4% to 31.9% among the 30 Networks (p <0.001). Adjusting for their patient characteristics did not appreciably reduce Network-level variation, with adjusted IR rates still ranging from 8.0% to 29.4% (p <0.001). The risk-model also suggested that non-white women and those from more deprived areas were less likely to undergo immediate reconstruction. Conclusions: There is substantial regional variation in immediate reconstruction use in England that is not explained by the characteristics of the local patient population. English Cancer Networks should act to reduce this variation. They should also examine why rates of reconstruction differ between particular patient groups.