Keratocystic Odontogenic Tumour (KCOT), formerly known as odontogenic keratocyst (OKC) has a high recurrence rate, which is a unique characteristic. Objectives: The present study was aimed at determining the presence of Collagen IV, Laminin 5, Matrix Metalloproteinase- 2 (MMP-2) and Matrix Metalloproteinase- 9 (MMP-9) in the basement membrane (BM) zone of KCOT in order to gain a better understanding of their role in the high recurrence rate of KCOTs. Methods:Haematoxylin and eosin-stained sections of 26 KCOT cases were grouped into I. Primary KCOT cases which had not recurred (KCOTnR) (n=12), II. Primary KCOT cases which had recurred (KCOTwR) (n=7) and III. Recurred KCOT (ReKCOT) (n=7). They were prepared for immunohistochemical staining for Collagen IV, Laminin 5, MMP-2 and MMP-9 with suitable positive and negative controls. Results:Group I showed Collagen IV expression in high percentage (75.0% cases) followed by Group II (28.6% cases) however this was not statistically significant; none of the Group III had positive staining.The expressions of Laminin 5, MMP-2 and MMP-9 at the BM zone were not significantly different between the Group I and Group II and between the Group II and III. Conclusion:Collagen IV, Laminin 5, MMP-2 and MMP-9 may be involved in the modulation of KCOTs' basement membrane integrity but may not be useful as a marker to predict the recurrence potential of KCOT.