This work investigated the applicability of rice husk ash as filler in ceramic tile mortar. Rice husks, obtained from a rice mill in Abakaliki were washed, dried and heated to char (carbonized) on a gas stove until there was no emission of fumes. The rice husk char obtained was incinerated under controlled conditions in a muffle furnace at 650oC for four (4) hours to produce rice husk ash (RHA). The ash obtained was ground to reduce the particle size and then sieved with a standard sieve to obtain particle size of ~187μm which was used as filler in ceramic tile mortar. The mechanical properties of the prepared mortar were determined and compared with those produced with CaCO3 as well as Top Fix, a popular brand in the Nigerian market, used as reference standard. The results showed that the RHA-filled mortar had higher bond strength (11.65 KPa), compressive strength (1290 KPa), and tensile strength (165 KPa) than the samples formulated with CaCO3. However RHA-filled mortar showed lower flexural strength than the CaCO3-filled samples. Rice husk ash mortar was found to be comparable to Top Fix, the commercial product.