Size is one of the most important features of an organism, as it affects many physiological and ecological characters. By varying one or more of the three major size components: maximum body depth, length, and width, fishes have evolved an amazing variety of body shapes, from dorsoventrally flattened batfishes and laterally flattened flatfishes through to more globular pufferfishes and elongate eels. To understand how this diversity has evolved we quantify the relationship between these three size components across 35 orders and 158 families of teleosts. The overall relationship patterns between standard length and depth or width comprise slopes close to one and high R² values. However, we also identified shifts in the slope, intercept, and R² values across the phylogeny. We also investigated whether these shifts in the relationship between the three size components impact clade-level dynamics. To do this, we gathered information on species richness, diversification rates, and age for each of these clades. We found that clades which deviate from the general teleost patterns are species poor and have lower lineage diversification rates, especially when exploring relationships between body width and standard length. However, the application of resampling strategies is still needed to rule out potential statistical bias regarding poorly sampled clades. Our preliminary results suggest that the relationships between the three size components are conserved across many clades and those clades that evolved altered relationships potentially incurred a macroevolutionary cost, at least when considering higher taxonomic levels.