The fatty acids in meat and fish, especially the n-3 and n-6 polyunsaturated fatty acids, are important from a nutritional point of view. In this sense, correctly identifying and quantifying fatty acids can be a tricky task. Nowadays, it is still quite common to find papers about food composition reporting fatty acid quantification, which does not reflect the actual food composition. This occurs when quantification is carried out using only the area percentage without considering important factors such as the lipid content of the food sample, detector response for the different fatty acids, and the use of an appropriate internal standard. Misidentification is also a common problem due to lack of standard availability or confirmation by mass spectrometry. This chapter will review the main methods for fatty acid analyses in meat and fish, emphasizing identification and calculation methods to generate reliable and accurate results.