This paper reports the dispersion of Montmorillonite nanoclay in vinylester using ultrasonication and co-rotating twin screw extrusion for preparing nanoclay/vinylester gel coat. Two sets MMT/vinylester specimens, namely Type 1 and Type 2 were prepared for comparative studies. While Type 1 specimens were prepared using ultrasonication only, Type 2 specimens were prepared using both ultrasonication and twin screw extrusion. Dispersion of nanoclay in vinylester was studied using XRD and TEM. Type 2 specimens showed lower levels of nanoclay agglomeration and higher levels of exfoliation. DSC results showed that glass transition temperature in Type 2 specimens is better than that of Type 1 specimens. The TGA results showed that the residual weight in 4 wt % MMT/vinylester of Type 1 was 7.38 % and the corresponding value for Type 2 was 13.5 %, indicating lower thermal degradation in the latter. By using the MMT/vinylester gel coat so prepared by the two different routes, MMT/vinylester/glass and MMT/vinylester/carbon specimens were fabricated and tested for mechanical and fire retardation behaviour. Type 2 based nanocomposite laminates showed greater values of ultimate tensile strength, flexural strength, interlaminar shear strength, impact strength, Horizontal burning rate, and Vertical burning rate than that of Type 1 based laminates. Scanning Electron Micrographs of tensile fractured Type 2 based laminates showed no or less agglomeration of nanoclay than that of Type 1 based laminates