This study aimed to assess the magnitude and patterns of fluctuating asymmetry as an indicator of developmental instability between two urban archeological Dutch populations. The sample comprised of 209 adult individuals representing the general population of Alkmaar, the Netherlands, dating to the 18th to early 19th century (Grote Kerk, n = 134), and a psychiatric hospital sample of the 19th to early 20th century (Meerenberg, n = 75). Fluctuating asymmetry was assessed from left and right measurements recorded from various traits on the cranium, mandible, and dentition. Three non-specific skeletal indicators of stress were documented to aid in the interpretation of the differences in asymmetry. No significant difference in developmental instability, as reflected by fluctuating asymmetry, was apparent between the two populations. However, individuals who presented with skeletal lesions indicative of stress were significantly more asymmetric than individuals who did not present with any of the lesions. The observed frequencies of the pathological changes and socio-economic history suggest that the two populations experienced similar levels of stress, even though the source and duration of the stress might have been different. The possibility that the mentally institutionalized are not as developmentally unstable as suggested by previous research should be considered.