Recently, a comprehensive clinical balance test, the balance evaluation systems test (BESTest), was developed to identify the postural control systems causing balance impairments. A short version, the mini-BESTest, was thereafter developed by eliminating redundant and insensitive items. This study aimed to translate the mini-BESTest to Swedish, adapt it and investigate its validity in subjects with Parkinson's disease (PD) or stroke. The Mini-BESTest was translated and back-translated in accordance with Guillemin's guidelines. Discrepancies were discussed and solved by a panel and the test was culturally adapted. Concurrent validity of the final version was explored by correlating well-known clinical tests - the Berg Balance Scale (BBS), the Timed Up and Go (TUG) test and the Falls Efficacy Scale (FES(s)) - with the new mini-BESTest in nine subjects with mild-to-moderate PD (60 years, range 46-85) and nine with chronic stroke (78 years, range 66-90). A high-to-very-high correlation was shown between the mini-BESTest and the BBS (PD: r(s) =0.94, stroke: r(s) =0.86). The mini-BESTest correlated highly with the TUG (PD: r(s) = -0.81, stroke: r(s) = -0.89). In the PD group, a low correlation (r(s) =0.26) was seen between the mini-BESTest and the FES(s). The mini-BESTest has high concurrent validity and is a comprehensive assessment of balance. However, its psychometric properties should be evaluated further.