Structural in-situ restoration interventions are widely employed to mitigate the impacts of urbanization on streams in developed countries. However, their effects on ecosystem functioning in urban tropical streams, particularly in Brazil, remain poorly understood. This study evaluates the short-term effects of cross-vanes and riffles on ammonium and soluble reactive phosphorus (SRP) uptake, as well as on whole-reach metabolism, in an urban tropical stream. Two 500-m reaches of the urban stream, subjected to different types of anthropogenic impacts, were selected for investigation. The first reach featured a natural substrate, degraded riparian vegetation, erosive features, and a meandering channel. The second reach displayed an altered substrate, degraded riparian vegetation, erosive features, a linear channel, and rainwater inputs. Restoration interventions were implemented across approximately 1 km of the stream, covering its entire length within the urban area, despite significant operational and logistical challenges. Metabolic rates and nutrient uptake metrics were assessed using the single-station method and the Tracer Addition for Spiraling Curve Characterization (TASCC) approach. Comparisons were made before and after the restoration interventions, as well as against reference conditions. Post-restoration, the stream substrate showed an increase in sand and pebble content, a reduction in gross primary production rates, and no significant changes in respiration rates or ammonium and SRP uptake efficiencies. The cross-vanes and riffles caused water to accumulate upstream, forming pools that increased the wetted width and water depth. However, sediment accumulation downstream of these structures led to a rapid decrease in water depth within days of installation. Despite some notable improvements, ecosystem functions in the restored reaches remained distinct from those observed in reference streams. These findings suggest that structural in-situ restoration in urban streams should be integrated with upland best management practices to improve overall effectiveness. This study provides critical insights for guiding future structural restoration projects in urban tropical streams.