Purpose Poor mesh tissue integration is thought to be responsible for hernia mesh repair failures years after surgery. The aim was to develop and validate a standardised abdominal wall mesh tissue integration index to facilitate research. Methodology The Index is a ratio scale defined pre-experiment to assess integration, fibrosis, adhesion and degradation behaviour of hernia mesh in vivo, using a series of standardised tools. The Index was validated by using a porcine model. Twelve brands of mesh were implanted into twelve Landrace-White pigs. Appropriate mesh were randomised to retrorectus and intraperitoneal space. Post-mortems with explantation of mesh-tissue complexes were performed at 2, 3, 4, 8 and 12 weeks. All explants were subjected to standardised testing as predefined in the Index. Results Multi-level linear regression analysis using maximum likelihood was performed. A strong fit of models was achieved for all four areas of the Index, with minimal residues. T-test was applied to contrasts using Satterthwaite's method. Integration was predicted by week 8 (p < 0.001) and beyond. Compared to polypropylene, no statistically significant difference in integration among meshes were observed, except for macroporous mesh (p = 0.011). Fibrosis was predicted by week 12 (p = 0.002), and infection (p = 0.002). Degradation was predicted by intraperitoneal mesh (p = 0.047). A reduction in adhesion was predicted by week 8 (p = 0.046) and 12 (p = 0.011). Conclusion The Index is a valid system at objectively grading mesh behaviour in the short-term. Longer-duration studies are needed to validate the Index further.