There is a clinical need to better understand and improve post-operative pain for patients undergoing laparoscopic repair of incisional hernia. The aim of this single-centre, double-blind, randomised controlled trial was to compare post-operative pain between absorbable and non-absorbable tack fixation in patients undergoing IPOM + repair. Patients with primary incisional hernia (size 3-10 cm), were randomised to either Reliatack™ (n = 27), an articulating-arm device deploying absorbable polymer tacks, or Protack™ (n = 36), a straight-arm device deploying permanent titanium tacks. The primary outcome was reported pain on activity using a visual analogue scale at post-operative day 30. Clinical and patient-reported outcome measures (PROMs) were assessed pre-operatively (day 0), and at 1-, 6-, 30- and 365-days post-surgery. No significant differences in reported pain 'on activity' were found at any timepoint. Less reported pain 'at rest' was found on post-operative day-1 with absorbable tacks (p = 0.020). Significantly longer mesh-fixation time (p < 0.001) and the use of more knots for fascial closure (p = 0.006) and tacks for mesh-fixation (p = 0.001) were found for the absorbable tack group. There were no differences in other clinical and PROMs between groups. For the whole trial cohort (n = 63) several domains in the Short-Form-36 showed a reduction from baseline scores at day 30 that improved at day 365. At post-operative day 30, 75.0% of patients reported 'a lot of pain' since discharge. This study found no difference in reported pain when choosing absorbable or non-absorbable tack fixation. The utility of "early" post-operative pain assessment as a comparator following incisional hernia repair needs clarification.