There are many culturally significant mud brick buildings that are under severe threat in seismic areas worldwide. Wall cracking is a common failure mode that is observed in such structures. This leads to the loss of the monolithic character of the wall and leads to an assemblage of broken blocks that act as individual elements. Structural grouting is one of the many repair techniques that can be introduced in some of these situations in order to reinforce structural stability into the cracked earthen structure with minimal disruption. The method of structurally grouting seismic cracks would mechanically repair the wall, achieve continuity and help reintroduce the lost monolithic character. It is one of the least intrusive strengthening techniques which would ensure maximizing the preservation of historic fabric and building integrity. Mud brick (adobe) that is the main building material used to construct these buildings which use locally available soil. Hence the proportion of soil, organic material and drying conditions differ from place to place and so can vary in terms of performance. As commercially manufactured traditional mud bricks are being used for research, all the data obtained from the research would be valid only for them. Several clay-based grout formulations (low pressure injection) have been tested for the rheological properties of grout after characterization of the mud brick is undertaken. Recommendations for further testing have also been included in the thesis for future use.