Recently published institutional guidelines for anatomic boundaries of the prostate bed clinical target volume (CTV) have raised concerns regarding the feasibility of high-dose delivery to the planning target volume (PTV) while respecting rectal and bladder dose-volume constraints. This study describes the prospective use of daily image guided intensity modulated radiation therapy (IG-IMRT), and reports the preliminary measures of acute toxicity in this group of patients. Between August 2007 and March 2008, 25 patients were enrolled on a prospective research ethics board approved clinical trial. All were CT-simulated with a full bladder and empty rectum, immobilized in a customized vacuum device. Seven field step-and-shoot IMRT plans were generated, prescribing 6600cGy in 33 fractions to the ICRU reference point. Dose planning objectives were as follows, in the order of priority: PTV D99 ≥ 5400cGy, posterior half of rectal wall (PostRW) 1cm3 ≤ 5500cGy, rectal wall 1cm3 ≤ 6600cGy, bladder wall 2 cm3 ≤ 6730cGy, penile bulb 0.5 cm3 ≤ 6600cGy, femur 1 cm3 ≤ 5500cGy and PTV V95 ≥ 95%. Dosimetry endpoints were measured using dose-volume histograms. Patient-reported acute radiation-induced toxicity was assessed weekly during treatment, and graded using the CTCAE v3.0 toxicity scale. PTV D99 ≥ 5400cGy was achievable in all cases with a mean dose of 5827cGy. PTV coverage was compromised to achieve the PostRW constraint, resulting an average V95 of 95.3% (range, 92 - 99% and SD = 2.0). Among the 25 patients, 60% had PTV V95 ≥ 95%. Dose constraints for other normal tissue were met. Grade 2 GU and GI toxicities were experienced by 8% and 32% of patients, respectively. One patient reported grade 3 GU toxicity due to voiding more frequently than once per hour, which resolved during the course of treatment. For patients who reported experiencing GI 2 toxicity, 4 of them required the use of medication for symptom management. The use of IG-IMRT technique is feasible in delivering high-dose to the PTV with minimal compromise to coverage while respecting normal tissue dose constraints. Preliminary acute toxicity data is considered acceptable. Ongoing investigation will continue to evaluate biochemical control and late toxicity.