Study Type - Therapy (case series) Level of Evidence4 OBJECTIVE To investigate the outcomes of laparoscopic partial nephrectomy (LPN) for endophytic tumours and those located near the hilum or the posterior upper-pole, as these pose a technical challenge. PATIENTS AND METHODS Technically challenging tumours were defined as endophytic, hilar, or at the posterior upper-pole (group 1), and were compared to tumours in other locations (group 2). We collected data prospectively for all patients undergoing LPN at our institution, including baseline patient and tumour characteristics, surgical and postoperative outcomes. Two-sided t-test or rank-sum test, and chi-square or exact tests were used as appropriate for comparison of continuous and categorical variables, respectively, with P < 0.05 considered to indicate statistical significance. RESULTS There were 184 patients treated with LPN (42 in group 1 and 142 in group 2) between 2002 and 2008 by one surgeon (A.L.S.). Groups 1 and 2 were similar in terms of baseline variables (age, sex, body mass index, comorbidities, previous surgery, renal function and haematocrit) and in tumour size. LPN for challenging tumours resulted in a higher rate of collecting system repair (78% in group 1, 61% in group 2, P = 0.03). However, operative (surgery time, warm ischaemia time, blood loss, intraoperative complications) and postoperative outcomes (renal function, nadir haematocrit, complication rate, hospital stay and positive margin rate) were similar between the groups. CONCLUSIONS With developing experience LPN can be safe for technically challenging renal tumours in well selected patients.