Introduction. Hip and knee replacements are predictable orthopaedic procedure with excellent clinical outcomes. Discharging or leaking wounds affect length of hospital stay, affect bed planning and predispose to superficial and potentially deep wound infection. Predictable wound healing therefore remains the first hurdle. This trial aims to study the effectiveness of portable disposable incisional negative pressure wound therapy (NPWT) dressings in hip and knee replacements. This trial aims to study the effectiveness of portable disposable incisional negative pressure wound dressings in hip and knee replacements and the impact on wound healing, length of stay and wound complications. Patients/Materials & Methods. Following ethical approval 110 patients each were randomised to ‘Control group’ and ‘Study group’. Patients in control group received traditional dressings and those in study group received an incisional NPWT (PICO) manufactured by Smith & Nephew. Post operatively, state of the wound, level of wound exudate, length of hospital stay and complications were documented. Results. The average length of stay for control group was 4.72 ± 0.69 (Mean ± SEM) and for the study group 3.79±0.19 (mean ± SEM. Eight percent of the control group patients had wound related complications as opposed to 2% complications in the study group. The mechanical and device related issues in the study group accounted to 10%. Discussion. There is little evidence as to whether wound dressing choices affect wound healing in incisional wounds. There is good evidence for negative pressure wound therapy (NPWT) in complex, open and chronic wounds; however the concept of application of NPWT to routine incisional wounds is novel. Advances such as disposable and portable negative devices have made this option attractive in elective surgery. Conclusion. Our study shows that its application in routine primary hip and knee replacement can improve wound healing, facilitate early and predictable discharge from the hospital and reduce post discharge complications. This is particularly true for high risk wounds such as patients with BMI of >35 and is cost effective