<p>Amphibians constitute the highest number (41%) of threatened species among the vertebrates. Globally, the group is facing many threats, including environmental pollution. The impact of nano-pollutants varies at different concentrations in the larvae of different amphibian species. Empirical data on various stressors and their impacts on endemic stream breeding amphibian species of Hindukush-Himalayan region are lacking. We therefore conducted the present study to see if engineered nanoparticles (iron and zinc) had any effect on the growth and development of Hazara frog (<i>Nanorana hazarensis</i>) and Murree Hills frog (<i>N. vicina</i>) tadpoles under laboratory conditions. Our results show that there is an effective range of zinc (up to 5&#xa0;mg L⁻¹) for Hazara frog where its bioavailability may be associated with significantly increasing growth rates. Conversely, we identified that zinc deficiency (concentrations below the detection limit) and excess (concentrations of ≧&#xa0;20&#xa0;mg L⁻¹) were both associated with slower or defective growth rates.&#xa0;However, higher concentrations of iron (≧&#xa0;10&#xa0;mg L⁻¹) delayed growth in Murree Hills frog. Our findings show that these species exhibited slower growth but faster development at higher concentrations of nanoparticles. We suggest further detailed long-term studies focusing on cytotoxicity, agglomeration of nanoparticles in the environment and body, mechanism of action and any changes at genetic level.</p>