It is recognised that those diagnosed with HIV infection over the age of 50 have higher rates of morbidity and mortality. Little is known about how clinical presentation at diagnosis of HIV varies within this group. We sought to compare clinical presentation and markers of outcome among those diagnosed with HIV aged 60 and over vs. those diagnosed aged 50–59, over a ten-year period. The results showed that 84/111 were diagnosed with HIV aged 50–59 and 27/111 aged ≥60. Ethnicity and HIV risk factors were similar between groups, and most infections were sexually acquired with 7.4% of those aged ≥60 suspected to have a recent infection. Median CD4 cell count at presentation was significantly lower in the ≥60 age group (111 vs. 249; p < 0.001), and the proportion with a CD4 cell count <50 was also significantly lower in this population (33% vs. 15%; p = 0.04). In keeping with this, the frequency of AIDS-defining illness at diagnosis was higher in the ≥60 group (38% vs. 4%; p < 0.001). Co-morbidities were found in both groups, and 38% of those aged ≥60 at diagnosis were known to have since died compared to 4% of those aged 50–59 at diagnosis (p ≤ 0.01). Those aged ≥60 had lower CD4 cell counts at diagnosis and more AIDS-defining illnesses, highlighting the increased risk of poor outcomes in this group. The majority of infections were sexually acquired. More work is needed to understand survival in adults diagnosed with HIV at an older age and to consider those over 60 as a specific population worthy of further research.