Heavy, proton-rich stable isotopes belong to the least abundant isotopes in the solar system. Their formation mechanisms and their stellar sources are most likely different from those of neutron-capture generated r- and s-process nuclei that comprise the majority of nuclides heavier than iron. Heavy p-nuclide abundances in meteorites are therefore potentially useful in deciphering distinct stellar contributions to the nascent solar system. We therefore conducted the first high-precision measurements of the heavy p-process isotope 180 W, achieving a typical precision of ±0.7 ε-units for ca. 300ngW. Measured samples comprise metals from magmatic- and non-magmatic iron meteorites, as well as metal from one H4 chondrite (NWA 926) and two reduced terrestrial basalts (from Disko Island, Greenland and the Dzheltul'ski massif from Eastern-Siberia, Russia).The analyzed iron meteorites show clearly resolvable 180 W anomalies of up to +6 ε-units. Conversely, the chondritic metal and both terrestrial samples exhibit 180 W abundances indistinguishable from the standard value. As cosmogenic effects during space exposure of the meteoroids may have affected the 180 W budget, cosmic-ray exposure of the meteorites has to be critically evaluated. We therefore propose a method to approximate cosmogenic contributions to the 180 W signatures in order to unravel nucleosynthetic 180 W abundance anomalies. Our study reveals significant cosmogenic effects only for the longest exposed meteorites, shifting 180 W anomalies always to lower values (average cosmic-ray correction-factors can be estimated to lie between 0.01 and 0.30 ε 180 W-units per 100Myr of exposure). Cosmogenic effects for most of the analyzed meteorites therefore appear to be negligible with respect to the analytical precision achieved for iron meteorites. In addition to cosmic-ray exposure, radiogenic effects can be caused by putative decay of 184 Os or by decay of 180 Ta in its ground state. Whereas potential alpha decay of 184 Os could shift 180 W anomalies to higher values (but only up to levels that are within the analytical error of ∼0.5 ε-units for most samples), no significant production of 180 W could have occurred from 180 Ta decay.Notably, we identified significant and systematic abundance variations in 180 W between different iron meteorite groups, indicating that these isotope anomalies are characteristic for their entire parent asteroids. Our finding of decreasing excesses in 180 W from early formed magmatic iron meteorites (+3.8±1.2 ɛ-units) towards later formed non-magmatic iron meteorites (+0.6±0.5 ɛ-units), the analyzed chondrite and both terrestrial rocks (−0.3±0.7 ε-units) may thus mirror progressive homogenization of 180 W in the early solar nebula. This overall trend is also supported by a co-variation between 180 W and metal segregation ages for the different iron meteorite groups as well as by a co-variation between 180 W deviations and the respective asteroidal accretion ages. Such an interpretation would suggest progressive homogenization of the solar nebula within about ∼2.5 to ∼6Myr.