The use of external active and passive tags to study locomotion, behaviour, and survival of fish has been common practice for decades. However, if tags significantly impact the organism's routine behaviour, tagging data may not accurately represent the general, untagged population. This study aimed to identify the effects of different external tags on profile drag (as a proxy for cost of transport) of fusiform teleost fish and how different tag attributes (tag size, antenna length, tag shape) affect drag. The results demonstrated that large, cylindrical tags located anteriorly increase drag more than if they are moved posteriorly, and that small, tapered shaped tags placed at locations other than at the base of the dorsal fin are the least drag-inducing.