Nile tilapia (Orechromis niloticus) is a species of fish of great importance in the world aquaculture scenario, standing out from the others due to its sensorial and market characteristics, as well as the absence of the "Y" spine and the unpleasant odor, one of the species most well accepted by consumers. Knowing the relevance of Nile tilapia, it is important to investigate characteristics and sanitary conditions of this species. Thus, the present study aimed to determine physicalchemical characteristics and sanitary quality of tilapia fillets commercialized in the city of Ponta Grossa, PR. Three different brands (A, B and C) of frozen tilapia fillet were purchased in the pontagrossense market. The samples were analyzed for pH, humidity, water activity (aw) and Coliforms at 45°. The results were submitted to analysis of variance (ANOVA) and Tukey's test (p<0,05), using the statistical program ASSISTAT (version 7.7). The samples of fillets of the brands A, B and C, presented pH 6,22, 6,25 and 6,19, respectively, with no significant difference between them. Therefore, the samples are in compliance with the Regulation of the Industrial and Sanitary Inspection of Products of Animal Origin, which recommends pHs lower than 7 for frozen fish. The results of the moisture content did not present significant difference (A:81.30%, B:78.06%; C:79.74%). The aw of the samples (A:0.9813; B:0.9881; C:0.9909) was high, with no significant difference between the results. The aforementioned results confirm the high perishability of the fillets. The count of Coliforms at 45° revealed that all brands (A: 2,8*104UFC / g; B:> 250 CFU / g; C:1.4 *105UFC/g) were not in accordance with current legal standards, representing food unfit for human consumption from the point of view of health and potential deleterious to the consumer. The three brands presented the physical and chemical characteristics of the products for food processing.