The results of a HST/WFPC2 snapshot imaging survey of selected symbiotic stars in 1999/2000 are presented. Seven sources - HD 149427 (PC 11), PU Vul, RT Ser, He2-104 (Southern Crab), V1329 Cyg (HBV 475), V417 Cen, AS 201 - were observed in filters F218W (ultraviolet continuum), F502N ([OIII]lambda 4959,5007) and F656N (Halpha); an eighth source, RS Oph, was observed in F437N ([OIII]lambda 4363), F502N and F656N. The presence of extended emission was detected in He2-104, V1329 Cyg and possibly HD 149427. In He2-104 we detected the [OIII] and Halpha counterparts to the inner lobes found in [NII] by Corradi et al. For V1329 Cyg, comparison with previously published HST/FOC results indicates expanding ejecta which may be associated with an ejection event in 1982 (+/-2 years) at a velocity of 260 +/- 50 km/s in the plane of the sky and at an assumed distance of 3.4kpc. We also present previously unpublished radio images of HD 149427, which we have obtained from the archives of the Australia Telescope Compact Array and which reveal the presence of extended emission at a similar orientation to that of the possible optical extension. Finally we also include HST/WFPC2 GO observations of AG Peg and detect possible extended emission in the F218W filter.