This study investigated the effects of shelter surface area (SSA) on the feeding, growth and survival of the donkey-ear abalone, Haliotis asinina reared in mesh cages (0.38×0.38×0.28m) suspended in flow-through tanks (water volume = 6 m³). Cages had sections of polyvinylchloride (PVC) that provided shelters with surface area of 0.22 m², 0.44 m² and 0.66 m². Hatchery-produced abalone with initial shell length of 32 ± 1 mm and wet weight of 7.5 g were stocked at 50 individuals cage⁻¹ that corresponded to stocking densities of ca. 227, 113 and 75 abalone m⁻² of SSA. The ratios of shelter surface area to cage volume (SSA:CV) were 5.5, 11 and 16.5. Abalones were provided an excess red seaweed Gracilariopsis bailinae (= Gracilaria heteroclada) at weekly intervals over a 270-day culture period. Feeding rates (18–20% of wet weight), food conversion ratio (26–27) and percent survival (88–92%) did not differ significantly among treatments (p > 0.05). Body size at harvest ranged from 56 to 59 mm SL and 52 to 57 g wet body weight with significant differences between abalone reared at SSA 0.22 m² and 0.66 m² (p < 0.05). Abalone reared in cages with 0.66 m² SSA grew significantly faster at average daily growth rates of 132 μm and 188 mg day⁻¹. Stocking densities of 75–113m⁻² SSA in mesh cages suspended in flow-through tanks resulted in better growth of abalone fed red seaweed.