To improve the understanding of the incidence of skeletal deformities in Senegalese sole (Solea senegalensis), a feeding trial was carried out to evaluate the effect of increasing dietary arachidonic acid (ARA) levels during the Artemia feeding period on larval growth and skeletogenesis. Larvae were fed from 8 to 50 days post hatching (dph) with Artemia nauplii enriched with three different levels of ARA: ARA-Low, ARA-Medium and ARA-High (1.0, 4.5 and 7.0% ARA of total fatty acids, respectively). Increasing levels of dietary ARA did not affect significantly the survival. However, it influenced growth; larvae from the ARA-M group presented the highest values of final standard length and dry weight (11.36 ± 0.47 mm and 5.86 ± 1.06 mg at 50 dph, respectively) and larvae from the ARA-H group the lowest ones (9.53 ± 0.27 mm and 2.47 ± 0.26 mg at 50 dph). The skeleton of larvae fed the ARA-M diet tended to be more calcified at 15 dph than that of larvae fed ARA-L and ARA-H diets. Larvae from the ARA-M group tended to show a higher incidence of fusion of hypurals 3 and 4 (34.4 ± 3.1%) at 50 dph than the larvae from the other groups (18.7 ± 1.6%, in average). The latter results reflected a trend to a higher degree of skeletal development rather than a deformity, this being in agreement with the higher larval growth of this group. Besides, ARA levels did not affect significantly the incidence of total skeletal deformities (41.4 ± 1.5% in average). Larvae from all dietary treatments mostly displayed fusions of the vertebra 43 and 44 (32.2 ± 1.3% in average). The amount of 4.5% of total fatty acid of dietary ARA during Artemia feeding period promoted the best growth and proper skeletogenesis in Senegalese sole larvae.