ABSTRACT Patranella, A.; Kilfoyle, K.; Pioch, S., and Spieler, R.E., 2017. Artificial reefs as juvenile fish habitat in a marina. This paper focuses on the use of small, inexpensive, artificial reef modules as replacement juvenile fish habitat within marinas. The research hypothesis was that the placement of small, structurally complex artificial reef modules would increase fish abundance and species richness relative to unmodified marina seawalls. Nondestructive visual surveys of fishes were completed monthly for 14 months for 12 artificial reef sites and 12 control (unmodified) sites within a small marina. Divers recorded species, abundance, and size class (0–2 cm, >2–5 cm, >5–10 cm, >10–20 cm, >20–30 cm, >30–50 cm, and >50 cm) for all sites. Data was statistically analyzed using analysis of variance and a post-hoc Student Newman-Keuls test. Total mean fish abundance and mean species richness were both significantly higher at artificial reef sites than at control sites. Analysis of mean abundance by size class found that the >2–5 cm, >5–10 cm, >10–20 cm, and >20–30 cm classes were significantly higher for artificial reef sites. Species richness analysis by size class found that classes >2–5 cm, >5–10 cm, >10–20 cm, and >20–30 cm were significantly higher at artificial reef sites. Fishes from the grunt (Haemulidae) and snapper (Lutjanidae) families contributed the most to the total abundance for both types of sites. These results support the research hypothesis and have vital implications for mitigating ecological impact to coastal fish nursery areas with the use of artificial structure.