Passive integrated transponder (PIT) tags are an important technology used to study ecology and behavior of animals including several stream fishes. In this study we investigated feasibility of using PIT technology to study ecology of juvenile Mugil cephalus (striped mullet) in Hawaiian streams. We quantified retention rates of PIT tags relative to an alternative tagging approach, visible implant elastomer (VIE) tags in the postorbital adipose tissue, for juvenile M. cephalus through a laboratory study. Next we conducted a field study of movement patterns of PIT-tagged juvenile mullet in a lowland Hawaiian stream (Waiāhole Stream) from early to mid-August 2014. For the laboratory portion of the study, 30 individuals (5–7 cm fork length) were randomly distributed among three treatments: PIT, VIE, and control (no tag) and held for 48 days. Tag retention was 100% for PIT-tagged and 0% for VIE-tagged fish. For the field study, 19 individuals (14.6–18.7 cm fork length) collected from Waiāhole Stream were implanted with PIT tags, and the movement of tagged individuals between the stream and its stream-mouth estuary/Kāne‘ohe Bay was inferred using a stationary PIT antenna array for 7 days. During that period, the antenna array registered 189 detections (97% during daylight hours, one missed detection) from five individuals, translating into 27 visits in total. Trip lengths to the estuary ranged from 45 min to 22 hr, with longer forays (≥10 hr) occurring primarily at night and shorter forays (<10 hr) occurring throughout daylight hours. Our results suggest that PIT tags are a feasible and effective marking technology for studying ecology of individual M. cephalus in streams, which paves the way for future research using this approach to study other aspects of their ecology.