Several sizes of cuboid and triangular prism samples of yellowtail fillets were used to analyze the temperature distribution and profiles during batch and pseudo-continuous ohmic heating (OH) at high frequencies (20 kHz) by experiments and modeling using a previously developed 3D model with some modifications. The thermal behavior of the fillets during OH was simulated using finite element method based on Maxwell's equations. Yellowtail fillets were heated from 20 °C to 80 °C during OH at 20 ± 0.05 V (or 50 ± 0.05 V). Specific heat and thermal conductivity of yellowtail fillets were calculated, and previously reported electrical conductivities were used in simulation. The simulated temperature history and temperature distributions of all samples were similar with the experimental results during both batch and pseudo-continuous OH. The small differences observed between experimental and simulated results were attributed to the air surrounded the samples and the scarce cooking loss of fish fillets drop during OH.