Streaked photoemission from nanostructures is characterized by size-and material-dependent nanometer-scale variations of the induced nanoplasmonic response to the electronic field of the streaking pulse and thus holds promise of allowing photoelectron imaging with both subfemtosecond temporal and nanometer spatial resolution. In order to scrutinize the driven collective electronic dynamics in 10-200-nm-diameter gold nanospheres, we calculated the plasmonic field induced by streaking pulses in the infrared and visible spectral range and developed a quantum-mechanical model for streaked photoemission by extreme ultraviolet pulses. Our simulated photoelectron spectra reveal a significant amplitude enhancement and phase shift of the photoelectron streaking trace relative to calculations that exclude the induced plasmonic field. Both are most pronounced for streaking pulses tuned to the plasmon frequency and retrace the plasmonic electromagnetic field enhancement and phase shift near the nanosphere surface. DOI: 10.1103/PhysRevA.94.051401 Recent advances in nanoscience and nanotechnologies are creating new avenues for designing and making nanometerscale metal structures which respond to irradiation with electromagnetic radiation by creating a tunable induced electric field near the metal surface [1,2]. This induced "plasmonic" field originates in the incident-field-driven coherent collective motion of conduction electrons which, when stimulated near its natural resonance (plasmon) frequency, generate a very large induced polarization in subwavelength-size structures on substrate surfaces [3-9] and isolated nanoparticles [10]. Near metallic nanospheres and for linearly polarized incident radiation [10][11][12][13][14][15][16], the oscillating induced polarization gives rise to oscillating plasmonic fields with dipole-like angular distribution oriented along the polarization direction of the incident radiation [17].Strong plasmonic field enhancement effects are linked to the local dielectric properties of the nanostructure and form the underlying physical phenomenon in established surfaceenhanced Raman spectroscopy (SERS) [18] and various prototype and suggested applications, such as attosecond nanoplasmonic-field microscopy [3] and nanoplasmonically enhanced photocatalysis [19] and light harvesting [20]. The detailed understanding of plasmonic excitations in solids requires imaging techniques that resolve their spatiotemporal evolution [3,16]. While ultrafast laser technology is available in many laboratories worldwide, allowing the resolution of various aspects of the electronic dynamics during the infrared (IR)-pulse-streaked extreme ultraviolet (XUV) photoionization of gaseous atoms with a precision of about 10 as [21], a promising emerging line of attosecond science targets the electronic dynamics in solids, biomolecules, and nanostructures [2,22]. These highly time-resolved investigations on solid targets address effects that are absent in isolated atoms in the gas phase, such as the propagation of photoexcite...