Increased excretion of albumin in urine (albuminuria) is an early indicator of kidney disease in patients with diabetes, and cardiovascular disease in healthy individuals. The relationship between urinary albumin levels and the risk of vascular disease is a continuous one and commences within the clinically defined “normal” albuminuria range. To fully investigate these relationships it is important to understand the variation of albumin excretion within the normal range. Clinically, the “gold-standard” measure of albuminuria is albumin excretion rate (AER) from a timed overnight collection. Due to variability of AER, multiple collections are needed for diagnosis. Timed collections are burdensome for patients and are often incomplete causing unreliable results. Therefore, spot (untimed) samples are often used that report the albumin to creatinine ratio (ACR). Creatinine is used to account for differences in urinary concentration. This work investigates the variability of albumin excretion in different collections and will determine which collection, first morning void (FMV), second morning void (SMV) or at a random time, is the best surrogate for timed collections in individuals with albuminuria within the normal range. Methods: 17 healthy participants collected their urine over a 36-hour period in different containers on 3 separate occasions. For each collection method the mean of three repeats was calculated for each participant and then the median value [interquartile range] among the participants was determined. Intra-individual reproducibility of different collection methods (coefficient of variation calculated from 3 collections) and the correlation of the ACR in spot samples with timed overnight AER (Spearman’s rank) were determined. Results: The median AER was 4.5 µg/min [2.7 – 6.9] during the day and 3.2 µg/min [1.2 – 4.0] overnight, although not significantly different (p=0.105). The median ACR in the FMV, SMV and random samples was 3.1 mg/g [2.3 – 4.5], 4.8 mg/g [2.8 – 6.6] and 4.8 mg/g [2.8 – 7.2] respectively. The intra-individual reproducibility of albumin excretion in the FMV, SMV and random spot samples was 15.9%, 22.1% and 22.6% respectively. The correlation of the ACR in FMV, SMV and random spot samples with timed overnight AER was 0.88, 0.54 and 0.59 respectively. Discussion: Albumin excretion is lower overnight than during the day, most likely the result of lower activity which influences albumin excretion. The FMV has the best reproducibility and the strongest correlation with the “gold-standard” timed overnight collection. A FMV sample is the best untimed surrogate of an overnight collection when investigating the “normal” albuminuria range.